Solar hot water FAQ's

Please find answers to the following FAQs below.

Do you need sunny, hot weather for solar heating to be efficient?
How much heat can a system produce?
Is the capital expenditure for a solar system more than a gas heated system?
Are the solar panels expensive?
How much CO2 will a panel save?
Does the system require high maintenance?
What is the payback time?
Would a system provide hot water at night?

Do you need sunny, hot weather for solar heating to be efficient?

No. Modern solar systems utilise indirect as well as direct light to produce heat. The UK is more southerly that parts of Germany, Denmark, Holland, Norway and Sweden where solar systems are much more commonplace.

How much heat can a system produce?

The temperature in a solar system can get as high as 200C. This allows a four square metre panel to produce in an average year 1.69MWh of energy, free fuel!

Is the capital expenditure for a solar system more than a gas heated system?

It's roughly the same, but the shortfall of the solar system (30%), needs to be supported by other sources.

Are the solar panels expensive?

A solar panel is about the same fitted price as a modern gas boiler.

How much CO2 will a panel save?

A 4 metre square panel will not generate CO2 in its operation and so does not contribute to the greenhouse affect. The amount of CO2 saved will depend on what fuel you are comparing it to.

Efficient gas boiler - 320kg CO2 per year.
Efficient oil boiler - 520kg CO2 per year
Electricity - 730kg CO2 per year

Why not calculate how much CO2 your household generates at:

www.natenergy.org.uk

Does the system require high maintenance?

No. A typical drain-back system only has one working part, the pump. An installation should last 25 years and requires a service visit every five years.

What is the payback time?

This is currently a hot topic of debate, fossil fuels are currently subsidised by the government and by the planet by some 90%. Payback will be determined by fuel price changes in the next 25 years. It also compares to what system you have at present. Don't forget that a solar system could also add value to your property.

Would a system provide hot water at night?

Yes, a properly designed system will store hot water overnight and existing heating will top it up if required.
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