• 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 →
  • January 8, 2013 - Cameron appoints Stephen Lovegrove as new head of DECC - Stephen Lovegrove is named as the new head of the Department of Energy & Climate Change (DECC), after David Cameron controversially intervened in the appointment process. - Lovegrove supercedes the candidacy of the chief executive of the... More →
  • January 2, 2013 - DECC updates Renewables Roadmap to include solar - The government has published a long-awaited update to its official Renewable Energy Roadmap, which details how it expects the clean energy sector to rapidly expand over the next eight years. - The original Renewables Roadmap published in 2011 caused... More →
  • December 14, 2012 - Improved Solartwin aesthetics - Solartwin is an incredibly simple and reliable solar thermal system. It boasts innovations including solar pv powered pumps and controls, silicone rubber pipes that do not require antifreeze, no scheduled annual maintenance and 1 day installation. -... More →
  • November 8, 2012 - Genfit acquires Solartwin website - Renewable energy news UK. Following the sad news of Solar Twin Ltd ceasing to trade on 31st July 2012, we are pleased to announce that solartwin.com has been purchased by Genfit. - Genfit is not new to Solartwin as its directors and management are... 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

0344 567 9032

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

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 companies. The organisation wants to see an end to doorstep selling by solar companies and a [...]

Read More | Archives

Cameron appoints Stephen Lovegrove as new head of DECC

Stephen Lovegrove is named as the new head of the Department of Energy & Climate Change (DECC), after David Cameron controversially intervened in the appointment process. Lovegrove supercedes the candidacy of the chief executive of the Committee on Climate Change (CCC), David Kennedy, who had been endorsed by an interview panel of senior civil servants [...]

Read More | Archives

DECC updates Renewables Roadmap to include solar

The government has published a long-awaited update to its official Renewable Energy Roadmap, which details how it expects the clean energy sector to rapidly expand over the next eight years. The original Renewables Roadmap published in 2011 caused dismay across the renewables sector as it omitted solar technologies, which the Department of Energy & Climate [...]

Read More | Archives

Improved Solartwin aesthetics

Solartwin is an incredibly simple and reliable solar thermal system. It boasts innovations including solar pv powered pumps and controls, silicone rubber pipes that do not require antifreeze, no scheduled annual maintenance and 1 day installation. The slimline lightweight collector, with glazing bar, gives a similar appearance to a roof light from afar. However, as [...]

Read More | Archives


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