Dorset – Off Grid Solar Water Heating Campsite
Portable Campsite Solar Water Heating Showers – Gravity Fed No Electricity Required
Thermosiphon Geyser solar water heating systems are a very cost effective way of producing hot water due to their simplicity in design and installation requirements. Usually more common in hotter climate countries a typical system will involve a standard solar panel, hot water cylinder and connection pipes.
We have developed a system which can now be used in Northern Europe. This system takes full advantage of heat energy and convection movement (hot water rises and cold sinks).
Convective movement of the liquid starts when liquid in the solar panel is heated, causing the liquid to expand and become less dense, and thus more buoyant than the cooler liquid in the bottom of the solar panel. Convection moves heated liquid upwards in the system as it is simultaneously replaced by cooler liquid returning by gravity. Hot liquid from the solar panel rises into the flow connection pipe, gravitates in to the cylinder and flows back through the return at a much lower temperature. This process continues naturally until the temperature of the water reaches an equilibrium with solar radiation input.
Early in 2016 Highwood Camping took delivery of two Thermosiphon Geyser systems which provide Free Hot Water.
A Thermosiphon Geyser hot water 150L tank system that would supply 2 showers (1 solar panel supplied) A Thermosiphon Geyser hot water 300L tank system that would supply 2 showers and wash up sink (2 solar panels supplied)
Our local plumber fitted the units on to the frames with the panels. The showers were fitted with blending valves and low flow shower heads to reduce water use. The system was tested and pipe work approved by Wessex Water before the grand opening of Highwood camping.
Because of the field use for agriculture for the main period of the year the Thermosiphon system and showers are mounted on trailers, this makes them very portable, easily towed into the field and plumbed in to the mains water supply.
The following are the actual results and performance of the first year use of our fully sustainable system, set against a back drop of the wettest year on record and low summer temperatures
1110 people stays over 28 days in late July and August (50% capacity) Used 22000 litres of water, which is an average of 20L of water a day. For water consumption this fares very favourably against the average household daily use per person of 130L. Of the water used approx 80% would be hot water presuming the hot/cold ratio on the blending valve would be 80/20, hot water would have been used for washing up, and cold water for washing/brushing teeth’
The Thermosiphon systems produced enough warm water to satisfy demands every day except one. The blending valves on the back of the showers were turned down on 3 days as the water was too hot. To note – Campers have a variable habit with regards to showers, from observations we would guess if you had 100 people on site 3 in 4 would shower every day. Campers welcomed the sustainable ethos at Highwood Camping and were all very impressed with the performance of the Solar Showers, feedback on the campsite listing sites have all been scored at 100% satisfaction.
In conclusions we saved considerable electricity expenditure, the exact amount is to be worked out as we have to find a like for like small site (TBC). For a small site such as ours the solar water heating units more than serve our purpose, if we were to double our capacity to 4400 person stays we would need to replace the 150L shower unit with a larger capacity unit. Probably the largest plus point when running a service business is that the sustainable nature of the campsite attracts a niche family market that want to stay on a site with Eco credentials, this leads to great feedback and happy clients.