I have solar panels on my roof.
And honestly…
They’re wicked.
They sit there doing absolutely nothing dramatic.
No noise.
No smoke.
No moving parts.
No fuel deliveries.
No giant engineering team turning up every morning.
They just quietly generate electricity and save me money.
Quite a lot of money, in fact.
Which makes solar power slightly unusual compared with most of the energy technologies I’ve looked at in this series.
I don’t have to imagine what it might be like.
I can see it working on my own electricity bill.
The misconception
When people hear solar power, they often picture enormous solar farms stretching across fields.
That certainly exists.
But one of the most interesting things about solar photovoltaic power is how small it can become.
A power station can sit on a warehouse.
A school.
A farm building.
A terraced house.
My roof.
That changes the relationship people have with electricity generation.
Most power stations are distant.
Hidden behind fences.
Connected to the grid through infrastructure most of us never see.
Solar panels bring generation directly onto the building using the electricity.
For once, the power station is not somewhere else.
It is above your head.
How does it actually work?
Solar photovoltaic panels convert sunlight directly into electricity.
There is no steam.
No turbine.
No combustion.
No fuel being consumed.
Inside each panel are photovoltaic cells, usually made from silicon.
When light strikes the cell, it transfers energy to electrons within the material.
Those electrons begin moving.
That movement creates direct current electricity.
The process is quiet.
Almost disappointingly quiet.
Nothing spins.
Nothing boils.
Nothing explodes.
Sunlight hits a semiconductor.
Electricity appears.
From the panel to the kettle
The electricity generated by solar panels is not immediately ready for normal household use.
Panels produce direct current, or DC electricity.
Homes use alternating current, or AC electricity.
An inverter converts one into the other.
The basic journey looks like this:
- Sunlight reaches the panels
- The photovoltaic cells produce DC electricity
- Cables carry that electricity to an inverter
- The inverter converts DC into AC
- The house uses the electricity first
- Surplus electricity is exported to the grid or stored in a battery
- Any shortfall is imported from the grid as normal
That means the electricity generated on my roof is usually consumed by the nearest available load.
The fridge.
The computer.
The washing machine.
The kettle.
Whatever happens to be running at the time.
The electricity does not need to travel across the country.
It may only travel a few metres.
The strange joy of using your own electricity
Once you have solar panels, you start thinking about electricity differently.
Before solar, I would turn the washing machine on whenever it was convenient.
Now I find myself looking outside.
Is it sunny?
Are the panels generating?
Could I run the dishwasher now instead of tonight?
It is a small behavioural change.
But it makes the energy system suddenly feel visible.
You begin matching demand to supply without really thinking about it.
The Sun is out.
Use the free electricity.
It becomes a tiny household version of what grid operators do every day.
Where do the panels come from?
Solar power may not require fuel after installation.
It still has a substantial manufacturing supply chain.
A typical solar panel depends on materials including:
- Silicon
- Glass
- Aluminium
- Copper
- Silver
- Polymers
- Electronic components
The process begins with quartz-rich raw materials.
These are refined into extremely pure silicon.
The silicon is then melted and formed into ingots.
Those ingots are sliced into very thin wafers.
The wafers are treated to create the electrical properties needed for photovoltaic cells.
Cells are then connected together, laminated between protective layers and sealed behind glass.
Finally, they are mounted inside an aluminium frame.
By the time a panel reaches a roof, it has already passed through mining, chemical processing, precision manufacturing, glass production, electronics assembly and international transport.
The fuel may be free.
The equipment certainly did not appear by magic.
The hidden supply chain
The solar industry depends on far more than panel manufacturers.
It relies on:
- Raw material suppliers
- Silicon refiners
- Cell manufacturers
- Glass producers
- Aluminium fabricators
- Inverter manufacturers
- Electrical wholesalers
- Roof surveyors
- Scaffolding companies
- Installers
- Grid operators
- Maintenance providers
- Recycling companies
At domestic scale, the finished system looks simple.
A few panels.
Some cables.
A box on the wall.
Behind it sits a global industrial network.
Why orientation matters
Solar panels do not need scorching heat.
They need light.
In fact, very high temperatures can reduce panel efficiency.
What matters more is:
- Roof direction
- Roof angle
- Shading
- Local weather
- Time of day
- Time of year
- Panel condition
A south-facing roof is generally attractive in the UK because it receives strong exposure across the middle of the day.
East-facing panels generate more in the morning.
West-facing panels generate more later in the afternoon.
Even north-facing installations can sometimes produce useful electricity, although usually less.
The design should match the building and the way electricity is used.
The weather problem
Solar generation changes constantly.
Clouds pass overhead.
The Sun rises.
The Sun sets.
Winter days are shorter.
Summer days are longer.
That variability is real.
It is also often misunderstood.
Solar power does not have to produce the same output all day to be useful.
It simply has to reduce the amount of electricity that needs to be generated elsewhere.
On a bright day, millions of rooftops and solar farms can collectively reduce demand on conventional power stations.
On a dull day, other parts of the grid take over.
Like wind, solar is not meant to do everything alone.
It works as part of a system.
The half-time kettle problem
People often talk about the famous surge in electricity demand when everyone puts the kettle on during the break in a major football match.
Solar panels are not designed to guarantee that demand can always be met.
That is not a failure.
It is simply not their job.
Electricity systems rely on a mixture of generation, storage and grid management.
Solar contributes when sunlight is available.
Batteries can shift some of that electricity into the evening.
Gas, hydro, nuclear, wind, interconnectors and other sources provide support at different times.
The mistake is expecting every technology to solve every problem.
No energy source does that.
Batteries change the equation
Without a battery, surplus electricity is usually exported to the grid.
With a battery, some of that energy can be stored for later.
The panels generate during the day.
The battery charges.
The house uses that stored electricity during the evening.
That increases the amount of locally generated electricity used on site.
It can also reduce exposure to higher electricity prices during peak periods.
The battery does not create energy.
It changes when the energy is available.
That distinction matters.
Storage turns solar from a daytime-only resource into something much more flexible.
Insurance and operational risk
Domestic solar systems are relatively simple.
They are not risk-free.
Roof condition
Panels may remain in place for decades.
That means the roof beneath them needs to be structurally sound.
Installing panels on a roof already approaching the end of its life can create unnecessary future costs.
Removing and reinstalling the array for roof repairs is possible.
It is not free.
Fire risk
Solar panels themselves are not constantly catching fire.
However, electrical faults can occur.
Poor connections.
Damaged cables.
Faulty isolators.
Inverter failure.
Installation quality matters enormously.
A well-designed system should include suitable protection, isolation and cable management.
Weather damage
Panels are built to withstand severe weather.
They still face:
- High winds
- Hail
- Falling branches
- Snow loading
- Water ingress
- Lightning-related surges
Roof-mounted systems must be fixed securely without compromising the building’s weatherproofing.
Inverter failure
Solar panels often have very long working lives.
Inverters may need replacing earlier.
The inverter works continuously whenever the system is producing electricity and contains more complex electronics than the panels themselves.
It is often the component most likely to require significant replacement during the life of the system.
Shading and dirt
A surprisingly small amount of shading can affect output.
Trees grow.
Nearby buildings appear.
Birds leave reminders of their existence.
Dust and debris accumulate.
Solar is low maintenance.
It is not necessarily no maintenance.
The grid challenge
Millions of small solar installations change how electricity networks behave.
Traditionally, electricity flowed in one direction.
From large power stations.
Through transmission lines.
Into local distribution networks.
Then into homes.
Solar allows homes and businesses to send electricity back the other way.
That creates new engineering challenges.
Voltage management.
Local network capacity.
Protection systems.
Export limits.
Smart inverters.
The grid was originally designed around consumers.
Solar turns some of those consumers into generators.
The land-use argument
Rooftop solar has one obvious advantage.
The land is already being used.
The roof already exists.
No additional field needs to be occupied.
No new reservoir needs to be created.
No village needs to move.
No fuel needs to be delivered.
Large solar farms are more controversial because they compete with agriculture, landscapes and other land uses.
That does not automatically make them wrong.
But it does mean location matters.
Warehouses.
Car parks.
Industrial buildings.
Schools.
Homes.
There is an enormous amount of existing surface area available before every open field needs to become an energy project.
The recycling question
Solar panels last a long time.
Eventually, they still reach the end of their useful lives.
That creates a growing recycling challenge.
Panels contain valuable materials including:
- Glass
- Aluminium
- Copper
- Silicon
- Small quantities of silver
Many of these materials can be recovered.
The difficulty is building recycling systems capable of handling very large future volumes economically.
Solar power is often presented as though the story ends once the panel is installed.
It does not.
Every panel eventually has to be removed, processed, reused or recycled.
A genuinely sustainable solar industry has to plan for the end as carefully as it plans for the beginning.
Why solar became so successful
Solar does not win because it is perfect.
It wins because it is modular.
A small system can power part of a house.
A larger system can cover a factory.
Thousands of panels can form a commercial solar farm.
The same basic technology scales from a calculator to a power station.
That is remarkable.
It also has very low operating costs once installed.
No fuel bill.
Few moving parts.
Limited routine maintenance.
Quiet operation.
Rapid installation compared with many conventional power projects.
The electricity is variable.
But when the system is generating, it is extraordinarily cheap to operate.
The strategic lesson
I started this article by saying my solar panels are wicked.
They are.
Not because they solve every energy problem.
They do not.
They will not power my house through every winter evening.
They will not single-handedly stabilise the national grid.
They will not keep the kettle boiling during every England match.
What they do is much simpler.
When the Sun is shining, they quietly reduce the amount of electricity I need to buy.
They save me money.
They reduce pressure on the wider grid.
They turn an unused roof into a small power station.
And they do all of this without making a sound.
After looking at giant dams, nuclear reactors, coal stations, offshore wind farms and fields of mirrors, there is something wonderfully ordinary about solar photovoltaic power.
No huge machinery.
No fuel train.
No turbine hall.
Just sunlight landing on the roof…
And a little less money leaving my bank account.
Gareth Winterman