Here is a nice example of using every bit of roof a property has. On the front of this house we have fitted eight panels on the garage, which faces east. On the back there is a south facing roof carrying another 16 panels. Put the two together and it is a big system, and it sets this home up for years to come. Let me explain why an east facing garage roof is well worth using, what it brings to the table, and how combining it with a south roof builds a properly future proof setup.
Why east facing is worth having
People sometimes assume only a south roof is worth bothering with. Not true. East facing panels run at around 75 percent of the output a south facing panel would give, which is a strong return, not a consolation prize.
What east facing does especially well is generate early. At this time of year, in summer, this garage array will start producing electricity at about half four or five in the morning. As the sun comes up in the east, those panels are first to catch it and they get going while the rest of the roof is still in shadow.
That early start is genuinely useful. It means you are generating right from the start of the day, covering the early household load before the south roof has properly woken up. East facing panels and the morning routine line up nicely.
Eight panels on the garage
A garage roof is often overlooked, which is a shame, because it is usually clear, simple and easy to work on. No dormers, no chimney, just a clean run.
Eight panels on this garage is a tidy block that makes use of space that would otherwise sit empty. With modern 465 watt panels, eight modules is a meaningful chunk of generation in its own right, not a token gesture. Adding it to the main array lifts the whole system into a different bracket.
Combining east and south for a big system
This is where it gets clever. On its own, eight east facing panels is a decent small array. On its own, 16 south facing panels is a strong family sized system. Together, they make a really big system that produces across a long span of the day.
Here is the shape of it:
- Early morning: the east facing garage panels lead, generating from around half four or five.
- Through the middle of the day: the south facing roof takes over and delivers its big steady output.
- Across the whole day: the two roofs between them keep production going for far longer than either could alone.
A wider spread of generation across the day matches how a household actually uses electricity, which means more of what you make gets used in the home rather than exported at a lower value. Using more of your own power is where the real savings sit.
Setting the house up for the future
Once we complete this install, this house is set up for the future. With a system this size, the owners are unlikely to have an electricity bill any time soon.
The plan, as with a lot of our customers, is to move to electric heating down the line, using air conditioning. These are air to air heat pumps, a very efficient way to heat a home with electricity. At the moment there is essentially no electricity bill here. Once electric heating goes in, there may be a small one in winter, but here is how that gets handled.
In summer this big east and south system produces far more than the house can use. That surplus goes back to the grid and earns money under the Smart Export Guarantee, the scheme that pays you for exported electricity. Those summer credits then offset the extra winter usage when the heating is running. Depending on how the heating is used, the export earned in summer can largely cancel out the winter draw, keeping the overall bill close to nothing.
Why this approach makes sense
The thinking behind a system like this is simple. Use all the usable roof, spread generation across the day, and size it generously so summer surplus pays for winter need.
- Use all the roof. The garage was clear, so it earns its keep instead of sitting empty.
- Spread the generation. East in the morning, south through the day, so you generate when you use power.
- Size it for the future. A big system now means it copes when electric heating is added later.
- Bank the summer surplus. Export credits in summer carry value across to winter.
That is what a future proof install looks like. Not the smallest system that pays for itself, but one sized for how the home will be used in five and ten years.
The bottom line
An east facing garage roof is well worth using. It generates early, runs at around 75 percent of south, and combined with a 16 panel south roof it makes a big system that produces from dawn to dusk. With electric heating coming later and summer export credits offsetting winter use, this home is set up to run at little or no electricity cost for years. We design systems that make use of every roof and plan for the future right across Cambridgeshire, Bedfordshire and Northamptonshire. If you have a garage or outbuilding roof you think could be working harder, call the office on 01480 400607 or request a survey through our website.
Jason Pope
Owner, Selec Group