• April 9, 2014 - Domestic Renewable Heat Incentive Released - Solar Thermal has got the great government funding through the Domestic RHI which it deserves! Solartwin Solar Thermal panels have just become not only a cost cutting and very green option to heat your water but now you will receive additional... More →
  • November 6, 2013 - Notice to Solartwin customers - Letter's from Stenfield & Co - A number of Solar Twin Ltd customers have been in touch this week to query a letter they have received from legal firm Stenfield & Co. - The content relates to Solar Twin Ltd's liquidation, and claims that customers "undoubtedly paid more than... More →
  • July 12, 2013 - Renewable Heat Incentive Updated - Solar Thermal to have Heavy Support - The Government have today released the Renewable Heat Incentive: The first step to transforming the way we heat our homes. If you are looking to buy a SolarTwin System contact Genfit. "the scheme will be open to anyone in these groups who installed... More →
  • May 27, 2013 - DECC announce they are doubling the RHPP grant for solar thermal from £300 to £600 - Solar Thermal Panels Receive Huge Renewable Heat Premium Payment - Solar Thermal has received a huge boost, it's a great time to buy a Solartwin Product. - Greg Barker tweeted about the scheme - - Big uplift for #RHPP Vouchers to put a shot in the... More →
  • February 14, 2013 - Solartwin DIY reviews - SolarTwin Reviews from Reviewcentre - "Review Centre is a community of real people, just like you, sharing their product and service experiences. - Our community of reviewers are a passionate bunch who want to help you discover what's right for... More →
  • January 17, 2013 - Crackdown on aggresive solar selling - YouGen, a leading consumer body serving the renewable and energy efficiency sectors, is calling for a change in the law after a review by the Office of Fair Trading revealed unscrupulous selling tactics by solar and other energy efficiency... More →

Solar panels. Photovoltaic solar energy. Solar thermal: solar power & PV module pumped solar hot water

Solar water heating systems RHPP and renewable heating premium payment

Solar panels? Is the PV pumped Solartwin solar water heating system suitable for my RHI solar subsidy project? Solartwin review of options.


Solar energy direct for your home – checklist – considering to buy solar water heating systems in UK / Ireland…

  • Yes, you get the best solar water heating system performance if you can face the solar panel mainly unshaded, roughly towards the sun. Solar water heating panels on south, southwest or southeast roofs are ideal. Even east or west roofs usually offer 75-85% of peak performance from a solar panel.
  • Easily, if you have a traditional low pressure vented hot water system. This means a hot water cylinder, with its cold tank above, usually in the attic. Thermal stores are an easy fit, too.
  • Yes, if, height-wise, there’ll be under 5 metres height (up or down) between the water level in the cold tank and the solar panel’s midline. OK in most homes.
  • Yes, if your hot water cylinder holds over 80 litres. Most are about 120 l.
  • Listed buildings, conservation area properties, national parks etc, may need consent for solar panels. Solartwin is normally viewed as a roof window by planners.

And high pressure solar plumbing options? Solar water heating solutions for high pressure hot cylinders or combination boilers may also be feasible using thermal stores. Please call us about thermal stores on 0344 567 90327.

How many Solartwin solar panels do I need? In UK/Ireland one 2.8 sqm solar hot water panel is the usual number in homes of 1-4 people.

Who uses Solartwin solar thermal systems? Want to do something significantly positive for the environment? Or do you use costly fuels, or live “off-grid” Homeowners, self-builders, pool owners, farmers, businesses and housing associations (eg. Berwickshire, Perthshire, South Yorkshire, Habinteg, Bournville Vilage Trust) use Solartwin. Some solar case studies are here.

Is the sun OK in UK or Ireland? Yes! (Spain can use smaller panels.) Specifically designed for Scotland, Solartwin also performs superbly in hot countries. It typically gives 30-70% of a home’s hot water a year and works in response to variable sunlight levels. Meteorologists say the June sun offers 6 times more solar energy than December’s. All solar water heating systems outside the tropics always need some top-up heat (eg gas, wood, oil, electric), most in winter.

What about other uses of solar panels, apart from washing and bathing (which are usually the best solar applications)?
We recommend that providing solar hot water for washing and bathing are optimal applications for solar heating (of any technology) in relatively cool climates such as UK and Ireland. In general, solar hot water uses for washing and bathing are usually preferable to solar central heating or solar electric installations. These recommendations are based on based on either “usability fraction” or “cost-benefit reasons”, as follows…

  • Solar central heating It’s cold in winter and at night because of the lack of sunlight. Unless you want radiators at full blast on sunny summer days, solar washing & bathing offers at least 2-3 times better value.
  • One Solartwin solar panel installation delivers around 2-5 times more energy than the same sum of money spent on a solar electric (photovoltaic) array.

Need I control water hardness?

Control for “direct” Solartwin solar water heating system installations is uncomplicated. First phone the water company for “parts per million calcium carbonate” (also called “ppm CaCO3″). If they quote one figure instread to a range (not two) figures, allow 20% tolerance i.e. add 20% to their figure i.e. treat a single figure of 200 as 240.

  • If hardness ever exceeds 200 ppm CaCO3 (very hard water) use either an ion-exchange (salt-regenerated) water softener or an “indirect” Solartwin. We supply and fit softeners. Please call.
  • At 100 – 200 (maximum) ppm CaCO3, you can use Fernox Superconcentrate Limescale Preventer. Your first little bag of crystals on a string is free. Simply hang it in the cold tank. Replace it twice a year. A free 6-monthly postcard reminds you. Fernox SLP is food grade. It costs about £10 from DIY shops. Or you can use an ion-exchange water softener or an “indirect” system.
  • Under 100 ppm, and with ““indirect” Solartwins, use no hardness control.

All other water hardness treatments or conditioners, including electromagnetic, magnetic, electronic, physical or ultrasonic methods must not be used. The above 200 ppm maximum thresholds are reduced to by a further 20% for all “fortic”type hot water cylinders as well as irregularly used hot water systems, such as in holiday homes.

Yes, Solartwin cuts global warming!
Solartwin not only saves energy and money. One single solar panel Solartwin solar water heating installation in UK or Ireland can cut your yearly carbon dioxide emissions by a quarter of a tonne if your water heating fuel is mains gas. If other fossil fuels, or electricity are saved then yearly saving can be up to a tonne or more!

Solartwin – for energy systems designed with you and our environment at heart. Time for a solar roof?

For speed, and for the sake of the environment, Solartwin offer feasibility checks and fixed price solar quotes by phone.
Unique in the world, Solartwin's phone survey now also uses online aerial photographs of your roof in most urban areas!

Unlike most solar surveys, our instant surveys and quotes are completely free and with no obligation.
Click here to request a survey

Or Call us on

0844 567 9032

Domestic Renewable Heat Incentive Released

Solar Thermal has got the great government funding through the Domestic RHI which it deserves! Solartwin Solar Thermal panels have just become not only a cost cutting and very green option to heat your water but now you will receive additional funding too! The Domestic RHI rates – Released April 2014 Ofgem have produced a […]

Read More | Archives

Notice to Solartwin customers – Letter’s from Stenfield & Co

A number of Solar Twin Ltd customers have been in touch this week to query a letter they have received from legal firm Stenfield & Co. The content relates to Solar Twin Ltd’s liquidation, and claims that customers “undoubtedly paid more than you should have and it is highly likely that you will have been […]

Read More | Archives

Renewable Heat Incentive Updated – Solar Thermal to have Heavy Support

The Government have today released the Renewable Heat Incentive: The first step to transforming the way we heat our homes. If you are looking to buy a SolarTwin System contact Genfit. “the scheme will be open to anyone in these groups who installed an eligible technology since 15th July 2009″ so if you have a […]

Read More | Archives

DECC announce they are doubling the RHPP grant for solar thermal from £300 to £600

Solar Thermal Panels Receive Huge Renewable Heat Premium Payment Solar Thermal has received a huge boost, it’s a great time to buy a Solartwin Product. Greg Barker tweeted about the scheme – Big uplift for #RHPP Vouchers to put a shot in the arm of the market ahead of full Domestic #RHI tinyurl.com/ktxz3o2 — Greg […]

Read More | Archives

Solartwin DIY reviews

SolarTwin Reviews from Reviewcentre “Review Centre is a community of real people, just like you, sharing their product and service experiences. Our community of reviewers are a passionate bunch who want to help you discover what’s right for you.” (Review Centre) We are well rated on review centre, this shows the excellent product quality of […]

Read More | Archives


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