Unfortunately the short answer in this case was a no.
There seems to be a massive premium locally for anything that will save you money, it’s almost like local businesses artificially inflate the prices because the resulting product system will save money.
Being a tekkie I like to figure out how things work and with family skills in the way of plumbing, contracted professional installation was not necessary. With this in mind we were looking for a system that we could buy for us to assemble.
Locally we approached a company called DHS, went to the show room to look at what they had to offer. The system they supply is made by Grant Solar and comprises of ‘Flat Plate’ solar collectors. The storage tank would have been their own brand ‘Eco-Store’ water cylinder.
Prices of these components were £1000 each for the solar collectors and we were told that we would need at least three panels to cover our demand. The cylinder was £2500.
This was prohibitively expensive as this did not include the pumps and controllers necessary to make the system work. This was also exclusive of insulation, pipe and the fittings necessary to install the system and make it work. Total component cost of £5500.
At this point I retreated and contacted company in the UK called ReplEnergy. I had previously dealt with them for a small wind turbine and photovoltaic panels. ReplEnergy supply the more efficient ‘Evacuated Tube’ panels. I approached them for a quote for all of the components necessary to install the system. The total for the system was £2525. This included the controller, pump and insulation. They knocked off the VAT and included in the price was the delivery to Guernsey.
Apples and apples or apples and pears?
Ok so the systems are not exact, like for like. So what are the differences?
The DHS system comprised of three ‘Flat Plate’ panels and the ReplEnergy system comprised of one ‘Evacuated Tube’ panel.
The DHS system included an own brand tank, the ReplEnergy system included a fairly generic Copper cylinder.
Firstly the panels. Flat Plate or Evacuated tubes?
There are different advantages and disadvantages between each technology. Evacuated Tubes are widely believed to be more efficient. See WikiPedia
http://en.wikipedia.org/wiki/Solar_thermal_collector
The way we figured it out was simples.
• DHS recommended a minimum of 3 flat plate panels at a cost of £3000
• ReplEnergy a panel twice as big as we need for £582.60
Our chosen panel was a sixth of the price and twice as big as we needed.
Secondly, the Tank?
DHS would have you believe that their tank performs some kind of magic. When I went through it the principals are quite simple. The tanks work as a form of heat storage. The solar collector and the immersion heat a volume of water in the tank. You then transfer this heat to radiators and hot water as you need it.
This was simple to apply to a tank from another supplier. Then tank we ended up ordering from ReplEnergy has two ‘Coils’ one for the solar collector system and one for the radiators.
A simple diagram explaining how the system works can be seen on this link
http://www.replenergy.co.uk/images/Solar%20thermal%20system%20thermal%20store.gif
In the next article I will explain some of the constraints of installing the system that are unique to our property but are worth understanding.
