The Kitchen Table Conversations
☕ Real Questions About Solar, Answered Honestly.
For more than fifteen years, I sat at kitchen tables across the UK talking to homeowners about solar.
I loved it.
No two conversations were ever quite the same and by the time I came off the road, I’d probably had more than 7,200 of them.
What always struck me was this.
Almost none of them invited me into their home to talk about solar panels.
They invited me in because they wanted to make the right decision.
Nobody ever invited me into their home because they wanted to buy solar panels. They invited me in because they didn’t want to make an expensive mistake.
The conversation rarely began with:
“Which solar panel should I buy?”
It usually started with something much simpler.
“Before you start measuring anything… can I ask you something?”
Those were always the best conversations.
A few years ago, that chapter of my life came to an unexpected end.
A severe bout of bilateral pneumonia led to multi-organ failure and a two-week coma. My family were told to prepare for the worst.
Thankfully, I recovered.
But it changed how I worked.
My children had a simple message.
“Dad… you’ve done enough miles.”
So I came off the road.
I no longer spend my days driving from house to house, but I still enjoy exactly the same conversations.
The difference is that today they’re written down here, so thousands of homeowners can benefit from the same straightforward answers I used to give over a cup of tea at someone’s kitchen table.
No jargon.
No sales pitch.
Just honest conversations to help you decide whether solar is right for you and, if it is, what kind of system genuinely makes sense.
Why We Created This
Most solar websites explain products.
We’ve chosen to explain the questions.
Because the right answer often starts long before anyone measures your roof.
If one of these conversations sounds like something you’ve been wondering yourself…
You’re in exactly the right place.
☕ More Conversations Are Added regularly
As the questions change…
these conversations will grow.
Because homeowners keep asking better questions…
and solar keeps changing.
Check back soon, or explore the Solar Decision Library for more detailed explanations.
Browse the conversations
Kitchen Table Conversation 001
Kitchen Table Conversation 002
Kitchen Table Conversation 003
Ready to Discuss Your Own Home?
If these conversations have helped you think more clearly about solar, the next step is a structured assessment built around your property, electricity use and future plans.
Speak to Us First
Prefer to talk it through? Call us for an initial conversation about your home and what you hope to achieve.
Email Your Question
Tell us what you’re considering and we’ll point you towards the most useful next step.
Begin Your Assessment
Start a structured solar performance assessment built around your property, electricity use and future plans.
Kitchen Table Conversation 004
Kitchen Table Conversation 005
Kitchen Table Conversation 006
Kitchen Table Conversation 007
Kitchen Table Conversation 008
Kitchen Table Conversation 009
Ready to Discuss Your Own Home?
If these conversations have helped you think more clearly about solar, the next step is a structured assessment built around your property, electricity use and future plans.
Speak to Us First
Prefer to talk it through? Call us for an initial conversation about your home and what you hope to achieve.
Email Your Question
Tell us what you’re considering and we’ll point you towards the most useful next step.
Begin Your Assessment
Start a structured solar performance assessment built around your property, electricity use and future plans.
Kitchen Table Conversation 001
It’s a great question.
In fact, if I were still travelling around the UK visiting homeowners, I wouldn’t be surprised if this became one of the most common questions over the next few months.
The short answer?
Sometimes it’s a good idea.
Most of the time, it isn’t the same thing at all.
Here’s why.
Imagine someone saying…
“I’ve seen a bicycle for sale. Is that comparable to buying a family car?”
Well…
Both will get you from A to B.
Both have wheels.
Both solve a transport problem.
But they’re built to do completely different jobs.
That’s exactly how I see these new plug-in solar systems.
From 27 August 2026, you’ll be able to buy certain plug-in solar systems from retailers including Lidl, B&Q, Currys and others.
For the right person…
they could be a perfectly sensible purchase.
If you rent a flat…
If you don’t have your own roof…
If you simply want to offset a little of your daytime electricity…
then a small plug-in panel could make sense.
But…
if you’re trying to reduce your electricity bills over the next twenty years…
run a battery…
charge an electric car…
or make a serious investment in your home…
you’re comparing two completely different things.
One is a small appliance.
The other is a properly engineered energy system.
A rooftop solar installation isn’t simply about fitting panels.
It’s about understanding:
• how much electricity your household actually uses
• when you use it
• whether a battery would genuinely benefit you
• your roof’s orientation and shading
• future electricity prices
• and how all of those pieces work together.
That’s why we always start with questions before we start measuring roofs.
Because the right system isn’t determined by how many panels fit.
It’s determined by what you’re trying to achieve.
So if someone asks me…
“Ronnie… should I buy the Lidl one?”
My answer would be…
“Maybe.”
Let’s first understand what problem you’re actually trying to solve.
Because once we know that…
the right answer usually becomes obvious.
Over the years, I’ve found that people rarely regret asking one more question before they spend thousands of pounds. They do sometimes regret not asking it.
☕ One More Thing…
Most homeowners don’t have just one question.
Over the years I’ve found that once one question is answered…
another usually follows.
That’s exactly why we created the Solar Decision Library.
It’s a growing collection of straightforward explanations designed to help homeowners make confident solar decisions before anyone climbs onto the roof.
→ Continue the conversation in the Solar Decision Library
Kitchen Table Conversation 002
Another very good question.
And it’s probably one of the questions I’m asked most often.
Before I answer it, can I tell you something that might surprise you?
The number of panels is almost never where an engineer starts.
That’s where many quotations start.
It shouldn’t be where the design starts.
If I were sitting at your kitchen table, I probably wouldn’t ask about solar panels for the first few minutes. I’d ask about you.
I’d want to know…
How many people live here?
Is somebody usually at home during the day?
Do you work from home?
Are the children likely to leave home soon?
Or perhaps return!
Then I’d ask…
Have you got plans for an extension?
A hot tub?
An electric vehicle?
A workshop?
Air conditioning?
A heat pump?
Because the system we design needs to suit the home you’ll be living in five years from now…
…not just today.
Only then would I start looking at your roof.
Is there any shading?
How does the sun move across the roof?
Are there chimneys?
Dormers?
Trees?
Different roof pitches?
Different roof orientations?
How old is the roof?
Will it need replacing in a few years?
These things can all influence the design far more than many people realise.
Then we’d look at the electrical side.
Where will the inverter go?
Will the consumer unit need upgrading?
Is there already a battery?
Is there an EV charger?
Will there be one later?
Will the Distribution Network Operator need to approve the connection?
Only now…
…do we start talking about panels.
And here’s the important bit.
An installer using 510W panels will probably recommend fewer panels than someone using 440W panels.
That doesn’t automatically make either quotation right or wrong.
They’re simply using different equipment.
What matters is whether the overall system has been designed properly for your home.
☕ If this were my house…
“Here’s what I’d do.”
I wouldn’t choose the company that promised the most panels.
And I wouldn’t choose the company that promised the fewest.
I’d choose the company that could explain why they recommended the system they had.
That’s usually where you’ll find the best design.
Kitchen Table Conversation 003
“Will I benefit by installing a storage battery, or are solar installers just trying to sell me one?”
That’s another question I’m asked a lot.
And I completely understand why.
Batteries aren’t cheap.
So before you spend several thousand pounds on one, I’d want to be absolutely sure it was going to earn its place in your home.
Then…
The first thing I’d probably ask you isn’t:
“How big a battery would you like?”
I’d ask…
“What are you hoping the battery is going to do?”
Then we’d go through a series of natural questions.
Some homeowners tell me…
“I don’t want my spare electricity going back to the grid if I can use it myself.”
Perfectly sensible.
A battery can often help with that.
Others say…
“I’ve heard I can charge it overnight on a cheaper tariff.”
Again…
That’s true in many homes today.
Others say…
“I’d like to charge the car first.”
Or…
“I’d rather heat my hot water before the battery starts charging.”
Modern systems can often be designed to prioritise different loads depending on the equipment installed and the homeowner’s goals. That’s why the design conversation matters just as much as the battery itself.
Then I’d say something like this.
Here’s the mistake I’d try to help you avoid.
Buying a battery because your neighbour has one.
Or because somebody told you every solar system needs one.
They don’t.
Some homes genuinely benefit.
Some don’t.
Some benefit later.
Some benefit immediately.
It depends on:
when you use electricity
whether anybody is home during the day
whether you have an EV
whether you have or plan a heat pump
your hot water system
your tariff
and what you want the system to achieve.☕ If this were my house…
I wouldn’t start by asking,
“Which battery should I buy?”
I’d start by asking,
“What problem am I trying to solve?”
If a battery solves that problem…
I’d recommend one.
If it doesn’t…
I’d rather you spend your money somewhere else.
Because the best solar system isn’t the one with the most equipment.
It’s the one that’s designed around the way you actually live.
“A battery doesn’t save you money because it’s a battery. It saves you money because it allows you to use electricity differently.”
Kitchen Table Conversation 004
“My roof doesn’t face due south and part of it falls into shade. Is solar still worth considering for my home, or will I be paying for panels that never perform properly?”
That is exactly the sort of question I would want you to ask before anybody starts counting panels.
Because the honest answer is not:
“Don’t worry. Solar works on every roof.”
And it is not:
“Your roof isn’t perfect, so forget it.”
The short answer?
Your roof does not have to be perfect for solar to make sense.
But its imperfections must be measured, designed around and reflected honestly in the figures.
A south-facing, unshaded roof is the easy one.
It receives strong sunlight through the middle of the day and makes the prediction relatively straightforward.
But most homes are not drawings on a piece of graph paper.
They have chimneys.
Dormers.
Trees.
Neighbouring buildings.
East- and west-facing slopes.
Sometimes three or four different roof sections.
That does not automatically make them unsuitable.
It means the person designing the system has to do some work.
If I were sitting at your kitchen table, I would want to understand where the shade comes from.
Is it a chimney casting a narrow shadow for part of the morning?
Is it a tree that shades half the roof throughout a winter afternoon?
Is it a nearby building that blocks the low sun for several months?
Or is somebody looking at a roof at ten o’clock on one cloudy morning and making a judgement about the whole year?
Those are very different situations.
I would also ask when you use electricity.
An east-facing roof produces more of its energy earlier in the day.
A west-facing roof produces more later in the day.
So if your household is busy in the morning, or everybody returns home in the afternoon, a roof that is not facing south may still produce electricity at a very useful time.
This is where I think the industry sometimes asks the wrong question.
It asks:
“How much electricity can we generate?”
I would rather ask:
“How much useful electricity can this home generate, and when will it be available?”
Those are not quite the same thing.
Then there is shading equipment.
You may hear words such as optimisers, microinverters, bypass diodes and multiple trackers.
They can all have a place.
But none of them manufactures sunlight.
An optimiser may help a system manage uneven conditions. It cannot make a heavily shaded panel perform like one sitting in full sunshine.
That is why I would never begin with:
“You need optimisers.”
I would begin with:
“Show me where the shade falls, how it changes through the day and what effect it is expected to have over the year.”
A proper design should be able to explain:
- which roof sections are being used
- why the panels are being placed there
- the expected annual generation
- the estimated effect of orientation and shading
- how the panels will be connected to the inverter
- and whether any extra equipment is solving a real problem
If the quotation simply shows the maximum number of panels that can be squeezed onto the roof, that is not yet an answer.
It is a panel count.
Here is another point people are rarely told.
The best-looking roof on paper is not always the best design for the homeowner.
Perhaps one awkward roof section adds very little useful generation but adds scaffolding, cabling and equipment cost.
Perhaps leaving those panels off produces a cleaner system and a better return.
Or perhaps using both east and west roof slopes spreads generation across more of the day and suits the family better than a smaller south-facing array would.
This is why “Is my roof suitable?” cannot be answered from the compass direction alone.
It has to be answered by looking at the home, the obstacles, the likely generation, your electricity use and what you want the system to achieve.
☕ If this were my house…
I would not reject solar because the roof was not due south.
And I would not accept a cheerful promise that shade would make no difference.
I would ask the designer to show me the difference.
Where will the system perform well?
Where will it be compromised?
What has been allowed for in the forecast?
And is the extra equipment earning its place?
If those answers were clear, I could make a sensible decision.
If they were vague, I would keep asking.
Because an imperfect roof can still support a very good solar system.
But only when the design is honest about the roof it is actually going onto.
Kitchen Table Conversation 005
“My quotation says solar will save me thousands of pounds and pay for itself in a certain number of years. How do I know those figures are realistic for the way we actually live?”
That may be one of the most important questions on the whole quotation.
Because large numbers printed in a colourful proposal can look very convincing.
Annual saving.
Twenty-five-year saving.
Payback period.
Return on investment.
Sometimes the figure is shown to the nearest pound.
That makes it look precise.
But precision on the page does not necessarily mean certainty in real life.
The short answer?
A savings forecast can be useful.
But it is only as believable as the assumptions underneath it.
If I were sitting at your kitchen table, I would not start with the twenty-five-year total.
I would ask how the first year was calculated.
How much electricity does the system expect to generate?
How much of that electricity are you expected to use in the home?
How much will be exported?
What price has been used for the electricity you avoid buying?
What export payment has been assumed?
If there is a battery, how often is it expected to charge and discharge?
And most importantly:
Do those assumptions resemble your household?
Imagine two neighbouring homes with identical roofs and identical solar systems.
In the first home, somebody works from home, the washing machine runs during the day and an electric car is often on the drive.
In the second, the house is empty from eight in the morning until six in the evening.
The panels may generate almost the same amount of electricity.
But the two households may use that electricity very differently.
That changes the saving.
Electricity used in the home replaces electricity that would otherwise have been bought from the grid.
Electricity exported is paid at the export rate available to the homeowner.
Those two units of electricity may have very different financial values.
So when a quotation quietly assumes that you will use a very high proportion of the solar electricity yourself, the savings can rise dramatically.
The question is whether your daily routine supports that assumption.
This is also why a battery should not simply be added to the forecast as a magic savings box.
A battery can move electricity from one part of the day to another.
It may also be used with a time-of-use tariff.
But it has a cost, a usable capacity, a maximum power output and some energy is lost in the charging and discharging process.
The calculation needs to reflect what that particular battery is expected to do in that particular home.
Then we come to the long-term forecast.
Nobody can tell you exactly what electricity will cost in fifteen or twenty years.
Nobody knows precisely how your household will change either.
Children leave home.
Sometimes they come back.
People retire.
They start working from home.
They buy an electric car.
They install a heat pump.
They move.
A long-term projection is therefore a model, not a promise.
That does not make it worthless.
It means it should be treated as a planning tool.
I would much rather see a sensible forecast with visible assumptions than an enormous headline number designed to make the quotation difficult to resist.
One of the simplest tests is to ask the company to change an assumption.
Ask them:
“What happens if I use less of the solar electricity myself?”
Or:
“What happens if electricity prices do not rise as quickly as this proposal assumes?”
Or:
“Show me the figures without the battery, then show me what the battery changes.”
If the person can explain the answer calmly, that is useful.
If the entire proposal depends on one optimistic assumption remaining untouched, you have learned something equally useful.
There is another distinction worth making.
Generation is an engineering estimate. Savings are a financial estimate built on top of it.
The roof, location, orientation, shading and equipment influence generation.
Your behaviour, tariffs, export rate and future plans influence the financial result.
Both sides matter.
But they should not be mixed together until nobody can see where the number came from.
☕ If this were my house…
I would not choose the quotation with the biggest twenty-five-year saving.
I would choose the one whose first-year assumptions I could understand.
I would ask for the expected generation, self-use, export, tariff assumptions and battery contribution to be shown separately.
Then I would look at a cautious case as well as the attractive one.
Because I do not need a salesperson to tell me the future with impossible certainty.
I need an engineer to show me what is known, what has been assumed and what could change.
A believable forecast is not the one with the largest number. It is the one you can take apart and still understand.
Kitchen Table Conversation 006
“If I install solar panels and a battery, will my home keep running during a power cut, or is whole-house backup something completely different?”
That question became very real for millions of people on 28 April 2025, when continental Spain and Portugal experienced a total blackout.
Most of us assume that if there are solar panels on the roof, and perhaps a charged battery on the wall, the lights will stay on.
It sounds logical.
Unfortunately, it is not automatically true.
The short answer?
A normal grid-connected solar system will usually shut down during a power cut.
A battery does not automatically give your home backup power either.
If you want the house, or selected parts of it, to keep running, that capability has to be designed into the system.
Why would solar panels switch off when the sun is shining?
Safety.
When the electricity network fails, engineers may be working on cables they expect to be dead.
A standard solar inverter must stop feeding electricity into that network.
The system cannot be allowed to create a small live island on a circuit people are trying to repair.
So the inverter disconnects.
That protection is essential.
But it means the simple sentence, “I have solar, so I’ll have power,” is incomplete.
If I were sitting at your kitchen table, my first question would be:
“What do you mean by backup?”
Do you want one emergency socket for a lamp, phone charger and router?
Do you want selected essential circuits, perhaps the lights, fridge, freezer and internet?
Or do you expect the entire house to continue as though nothing has happened?
Those are three very different designs.
Whole-house backup sounds wonderfully simple.
But a home can ask for a great deal of power at once.
An electric shower.
An induction hob.
An oven.
A kettle.
A heat pump.
An electric vehicle charger.
A battery may contain enough energy to keep some essentials running for hours, yet still be unable to start or supply every high-power appliance at the same time.
That is the difference between energy and power.
Battery capacity, measured in kilowatt-hours, tells us broadly how much energy is stored.
The inverter’s output, measured in kilowatts, limits how much power can be delivered at any one moment.
You need to understand both.
A ten-kilowatt-hour battery is not a promise that every appliance in the home can run normally.
Nor is “backup included” a complete specification.
I would want to know:
- which circuits will remain live
- whether the changeover is automatic or manual
- the maximum backup output
- what happens if several appliances start together
- how much of the battery is reserved for an outage
- whether the panels can recharge the battery while the grid remains down
- and how the system is safely isolated from the network
That last point about recharging matters.
Some properly designed systems can continue using solar generation while operating in backup mode.
Others may provide battery power but cannot restart or recharge from the panels in the way the homeowner expects.
The equipment, wiring and control arrangements all matter.
Then there is duration.
If the battery is nearly empty when the power cut begins, the result will be different from an outage that starts with a full battery.
If it is a bright summer afternoon, solar may be available to help a suitably designed system.
If it is a winter evening, you are relying on the energy already stored.
That is why the right conversation is not:
“Would you like backup? Yes or no?”
It is:
“What must continue working, for how long, and under what conditions?”
For one homeowner, keeping the fridge, lighting and broadband alive may be enough.
For another, medical equipment, a water pump, security system or home office may make backup far more important.
And for somebody expecting to run an all-electric home through a long outage, the design needs much more careful thought.
☕ If this were my house…
I would decide which loads were genuinely essential before I decided how much backup equipment to buy.
I would ask the installer to show me exactly what stays on when the grid goes off.
Not in a brochure.
On my electrical circuits.
I would ask them to explain the power limit, the likely duration and whether the solar panels can keep contributing during the outage.
And when the installation was complete, I would want the backup operation demonstrated.
Because the middle of a power cut is a poor time to discover that “battery ready”, “EPS available” and “whole-house backup” do not mean the same thing.
Solar panels, a battery and backup power can work together beautifully. But only if backup was part of the design, not an assumption made after the sale.
Kitchen Table Conversation 007
“My quotation shows 5.2 kW of solar panels, but the inverter is only rated at 3.68 kW. Am I paying for electricity the inverter will never let me use?”
August 2026
That is exactly the sort of detail a careful homeowner should notice.
You have added up the panel ratings, looked at the inverter specification and found that the two numbers do not match.
It is perfectly reasonable to ask whether part of the system has been deliberately restricted.
The short answer?
A larger solar-panel array paired with a smaller inverter is not automatically a design mistake.
Sometimes it is a sensible way to produce more useful electricity across the year.
But it should be a calculated decision, not a number that the salesperson asks you to ignore.
First, those two figures describe different things
The 5.2 kWp figure is the combined peak rating of the solar panels on the DC side of the system. The 3.68 kW figure is the maximum AC output the inverter can deliver to your home and the electricity network.
In plain English: the panels collect the energy; the inverter is the controlled doorway through which that energy enters the house as usable electricity. A larger roof of panels can feed a smaller doorway, provided the doorway has been chosen deliberately and the flow through it has been calculated. |
The letters matter. Panel capacity is normally expressed as kilowatt-peak, or kWp. That is a laboratory rating under standard test conditions. Your roof will not sit at those test conditions for every hour of every day.
Panel temperature, roof direction, pitch, shading, cloud cover and the strength of the sunlight all affect the power available at any particular moment.
A 5.2 kWp array therefore does not continuously deliver 5.2 kW. Much of the year it will produce considerably less.
Why would an engineer specify more panel capacity than inverter capacity?
Because the objective is usually to improve useful annual generation, not to preserve every possible watt during a handful of exceptional peaks.
Additional panel capacity can help the inverter reach a useful output earlier in the morning, remain productive later in the afternoon and perform more strongly during dull or changeable conditions.
Think of it this way: a watermill designed only for the heaviest downpour of the year would be unnecessarily large for most days. A well-matched system is designed around the flow it will receive across the whole year, not one brief summer cloud break. |
This design approach is often called DC oversizing or an elevated DC-to-AC ratio. Used properly, it can increase the amount of energy produced over the year relative to the inverter cost and capacity.
What is clipping?
If the panels are capable of supplying more power than the inverter can process at that moment, the inverter holds its output at its maximum rating. The top of the potential production curve is then flattened. That is called inverter clipping.
In everyday terms: imagine filling a measuring jug from a tap. If the tap briefly supplies water faster than the jug’s spout can pour it away, the flow has to be held back. The inverter does not secretly store that extra potential. It simply prevents the system from converting more than its rated output at that moment. |
A small amount of predicted clipping may be entirely acceptable if the larger array produces worthwhile gains during the many hours when sunlight is weaker.
A large amount of clipping can be poor design. The important figure is not whether clipping exists. It is how much annual energy the design predicts will be curtailed, and what the homeowner gains in return.
The 3.68 kW figure can also involve the electricity network
On a typical single-phase property, 3.68 kW corresponds to 16 amps per phase. Installations within the relevant G98 limit can normally be notified to the Distribution Network Operator after commissioning. Systems above that threshold generally require the appropriate G99 application and approval process.
In plain English: G98 is broadly the notify-afterwards route for smaller generation. G99 is the ask-and-obtain-approval route for larger generation. Neither route means that every house must be limited to 3.68 kW forever. |
There is another possibility. A system can have a larger inverter or array while using an approved export-limitation arrangement under G100. This controls how much electricity crosses the boundary into the local network.
Export limitation is not the same as inverter sizing. One controls what may leave the property. The other controls what the inverter can convert. A careful proposal should make the distinction clear.
What should your quotation show?
Before accepting a design with 5.2 kWp of panels and a 3.68 kW inverter, ask for the following:
- The predicted annual generation for the proposed array and inverter combination.
- The estimated annual energy lost through clipping or curtailment.
- The reason that particular inverter size has been selected.
- Confirmation that the panel voltage and current remain within the inverter manufacturer’s permitted limits.
- The DNO connection route and any agreed export limitation.
- How a battery, electric vehicle or future heat pump would affect the design.
Be cautious if the only explanation is, “That is the legal limit,” because that is incomplete.
Be equally cautious if you are told that clipping can never occur. With a deliberately oversized array, some clipping may be predicted. The installer should be able to quantify it rather than deny it.
If this were my house
I would not reject the quotation simply because the panel and inverter figures were different.
I would ask to see the design reasoning.
If the figures showed that a modest amount of peak production was being exchanged for stronger generation across mornings, afternoons and poorer weather, that could be a sound decision.
If nobody could explain the mismatch, show the annual effect or distinguish the inverter limit from the export limit, I would not be ready to proceed.
A solar system should not be judged by whether all the numbers on the first page match.
It should be judged by whether those numbers work together for your roof, your electricity use and the performance you expect over the life of the system.
→ Continue the conversation in the Solar Decision Library
Kitchen Table Conversation 008
“If my panels are producing more electricity than my home can use and the battery is already full, where does the rest of the electricity go, and will I be paid for all of it?” |
August 2026
This is one of those questions that sounds simple until three different people give you three different answers.
One says the electricity automatically goes to the grid.
Another says the inverter wastes it.
A third says you will be paid for every unit the panels produce.
All three statements can be misleading without the rest of the explanation.
The short answer?
Your solar electricity normally follows a sequence: the house first, then the battery, then the grid, subject to the way the system has been designed and the export permission in place.
And no, payment is not automatic merely because electricity has left your property.
Where the electricity goes
When the panels are generating, the inverter and monitoring equipment continually balance production against what the property is using.
In a typical arrangement, the electricity is allocated in this order:
- Your home uses the solar electricity it needs at that moment.
- Any surplus may charge the battery, provided the battery has available capacity and can accept power at the required rate.
- Once household demand has been met and the battery cannot accept more, the remaining electricity may be exported to the grid.
Think of three destinations: the kitchen tap is the home, a water tank is the battery, and an overflow pipe is the grid. The system serves the open tap, fills the tank, and only then sends surplus through the overflow, unless its controls or permissions require a different strategy. |
A full battery does not mean the panels must keep producing at full power
Solar generation is controlled electronically. If the home cannot use the energy, the battery is full and the system is not permitted to export all the available surplus, the inverter can reduce the power drawn from the panels.
This is known as curtailment. It means some potential generation is not harvested because there is nowhere permitted or useful for it to go at that moment.
In plain English: the sunshine has not been put into a hidden storage cupboard and the electricity has not spilled onto the floor. The system has simply turned the tap down before that extra electricity is produced as usable AC power. |
Curtailment can happen because of an inverter limit, an export limit imposed through the grid-connection agreement, or a control setting within the system.
Export capacity and export payment are not the same thing
The Distribution Network Operator decides how much generation may be connected and, where applicable, how much electricity may be exported through the property connection.
Your electricity supplier deals with the tariff that pays you for measured export.
Put simply: the DNO controls the width of the road; the energy supplier decides whether it will pay you for the traffic recorded travelling along it. |
A system might therefore be technically capable of generating more than the property is allowed to export. An approved export-limitation scheme can keep export within the agreed level while still allowing solar electricity to serve the house and battery.
Will you be paid for everything exported?
Only if the export is eligible, correctly metered and covered by an export tariff that you have joined.
Under the Smart Export Guarantee in Great Britain, participating suppliers pay for eligible electricity exported to the grid. However, joining a tariff is not automatic when the installation is switched on.
You will normally need the appropriate installation documentation, a compatible smart meter capable of recording export and an export account or MPAN arranged through the supplier.
The precise requirements and rates vary between suppliers and tariffs.
Until the export arrangement is active, surplus electricity may still flow to the grid without generating a payment for you.
The app is not necessarily the payment meter
The inverter or battery app may show estimated production, consumption and export. Those figures are useful for understanding system behaviour, but your export supplier normally pays against the approved meter data used for settlement.
Do not assume that every green bar shown as “export” in an app will appear immediately as money on your electricity account.
A simple example
Imagine the panels could produce 6 kW at a particular moment.
- The house is using 1 kW.
- The battery is full.
- The agreed export limit is 3.68 kW.
The system may supply 1 kW to the house and export up to 3.68 kW. The remaining potential output may be curtailed, depending on the equipment and control arrangement.
If an active export tariff is in place, the metered export may qualify for payment at that tariff’s rate. If no export tariff has been activated, the same physical export may earn nothing.
What should you ask before installation?
- What proportion of the predicted generation is expected to be used in the home, stored and exported?
- What export level has been requested or agreed with the DNO?
- Will the system include export limitation, and under what circumstances will it curtail production?
- Who will provide the documents needed to apply for an export tariff?
- Is the financial illustration assuming a particular export rate, and could that rate change?
- How quickly can the battery charge, rather than simply how much energy can it hold?
If this were my house
I would want the proposal to show the energy journey, not merely the total annual generation.
A prediction of 5,000 kWh means very little on its own if nobody explains how much is likely to be used, stored, exported, curtailed and paid for.
I would also make sure the export application was not treated as an afterthought.
The best-designed system gives each useful unit of electricity somewhere worthwhile to go and explains honestly what happens when there is nowhere left for it.
kitchen table conversation 009
“The quotation says the solar panels have a 25-year warranty. Does that mean the whole system is protected for 25 years, and what happens if the installer is no longer trading?” |
August 2026
No.
A 25-year statement alongside the solar panels does not normally mean that every component, every repair and every labour cost is covered for 25 years.
It may be a valuable warranty.
But first you need to know which warranty it is.
The short answer?
A solar installation is protected by several different warranties and guarantees, supplied by different organisations and covering different risks for different lengths of time.
The number “25 years” is the beginning of the question, not the end of it.
The 25-year figure is often a performance warranty
A panel performance warranty normally promises that the panel will retain a stated proportion of its original rated output after a particular number of years, subject to the manufacturer’s terms.
In plain English: it is similar to a car manufacturer promising that an engine should still deliver a certain level of performance after long use. It is not the same as promising to repair every part of the car, pay every mechanic and supply a replacement vehicle for 25 years. |
A panel can have a long performance warranty and a shorter product warranty covering manufacturing defects.
Those are two different protections, even when both appear on the same brochure.
The rest of the system has its own protection
Your installation may include several separate warranty documents:
- Panel performance warranty: covers the rate at which panel output is permitted to decline under the stated test conditions.
- Panel product warranty: covers qualifying defects in the physical panel for the stated term.
- Inverter warranty: covers the inverter under its own manufacturer’s conditions and period.
- Battery warranty: may be limited by years, charge cycles, energy throughput, retained capacity or a combination of them.
- Workmanship guarantee: covers qualifying faults caused by the installation work itself.
- Insurance-backed workmanship protection: may preserve the installer’s workmanship guarantee if that installer ceases trading, subject to the policy terms.
Mounting equipment, optimisers, monitoring devices, EV chargers and other accessories may each have different terms again.
Parts, labour and access costs
A manufacturer may agree that a component is defective and supply a replacement part. That does not always mean it will pay for diagnosis, scaffolding, removal, shipping, reinstallation or the labour needed to replace it.
Think of a replacement roof tile: the tile itself may be free, but someone still has to reach the roof, remove the damaged tile and fit the new one. With solar equipment, the access and labour can cost considerably more than the item being replaced. |
This is why “parts and labour” is a more useful phrase than “warranty included.”
Ask who pays each cost and whether the answer changes after the installer’s own guarantee has expired.
What if the installer is no longer trading?
The answer depends on the fault and the documents issued when the system was installed.
If a panel, inverter or battery has a valid manufacturer warranty, the claim may still exist even if the original installer has disappeared. But you will need to know the manufacturer’s claim route and whether another competent installer can undertake the work without affecting the warranty.
If the problem is faulty workmanship, the manufacturer’s warranty may not help because the product itself may be perfectly sound.
That is where insurance-backed workmanship protection matters. RECC members must arrange for the term of their workmanship guarantee to be honoured through insurance-backed protection if they become insolvent or cease trading, subject to the applicable policy and conditions.
In everyday terms: the manufacturer’s warranty follows the product; the workmanship guarantee follows the installation work; the insurance-backed policy is intended to keep the workmanship promise alive if the installer can no longer do so. |
MCS certification provides important quality and consumer-protection requirements, but an MCS certificate is not itself a blanket 25-year warranty for the complete system.
Registration and paperwork matter
Some product warranties must be registered within a specified period. Some extended terms apply only when the equipment is installed, commissioned or connected in accordance with the manufacturer’s requirements.
Insurance-backed policies may also impose notification periods and claim conditions.
A promise mentioned during a sales conversation is difficult to rely upon if the corresponding certificate, policy or warranty document never arrives.
Your handover pack should identify the equipment installed and include the relevant certificates, guarantees, warranty information, system design and operating instructions.
Questions to ask before paying a deposit
- Is the 25-year panel promise a product warranty, a performance warranty or both?
- Who is legally providing each warranty: the installer, manufacturer, distributor or insurer?
- How long are the inverter, battery, mounting system and workmanship covered?
- Are diagnosis, labour, scaffolding, shipping and replacement installation included?
- Does any warranty require online registration, regular servicing or particular operating conditions?
- Which insurer provides the insurance-backed workmanship protection, and when will the policy document be supplied?
- Is the protection transferable if the property is sold?
- Who should the homeowner contact if the installer is no longer trading?
What should make you cautious? Be wary when every component is described as having “a 25-year warranty” without separate documents, when performance, product and workmanship protection are treated as the same thing, or when nobody can name the insurer behind the insurance-backed workmanship policy. |
If this were my house
I would choose the proposal that clearly set out what is covered, for how long, by whom and at whose cost, not simply the brochure displaying the largest warranty number.
Long-term protection comes from good equipment, competent installation, properly issued documents and a route to put things right if either a product or the workmanship fails. That is the reassurance worth buying.