Installing solar panels is often the first thing you think of if you change to sustainable energy. As most of our energy is used for heating, often a solar boiler also comes to mind. The problem was however that it would take away some space on the roof. Precious space you needed for solarpanels. 

With PVT this problem is solved. These solar panels can also be used as primary source for warm water. Primary source means that usually a gas heater or electric heater must be used as secondary after the summer.

Our PVT solar panel delivers an average water temperature of 25 degrees and up to 50 degrees in summer. In summertime this is enough to be used as a solar boiler, but special is that the PVT panel once the summer is over still provides enough warm water to be used as a 'closed-circuit-water-source' for a heating pump.

This so-called water source heat pump differs from an air source heat pump in that there is no exterior part like an outdoor air conditioning unit, well known for its noisiness which makes it often difficult to find a suitable place to install.

The water source heat pump is a simpler device because it lacks this outdoor unit and therefore is a lot cheaper. You can easily find room for it to place it indoors.

Such a water source heat pump is the same as used in (aquifer) thermal energy storage systems - in the Netherlands called WKO - using water from deep underground as a source to extract heat. These can be very expensive systems the deeper this groundwater is pumped up. Cheaper systems making use of geothermal baskets work in the same way, but they need a lot of lot space. With PVT you combine a cheap water source heat pump simply with the sun boiler part of the PV solar panels.

No need of expensive drilling, no need to destroy your garden and no need to install air-pump equipment which makes annoying sounds to you and your neighbours.

Energetic there is a huge benefit. The temperature of a PVT panel is usually more than twice as high as water extracted from the underground as source for the heat pump. To create the same output temperature for domestic heating give or take only half the electric power is needed. We measured impressive improvements on SCOP.

It was already known that water source heat pumps use less current than air source heat pumps, but in combination of the relative warmth of PVT as the water source the performance is even better. Even on clouded days the warmth of PVT can grow up to more than 20 degrees. If in case we have a longer period of frost, and little sunshine, the heating capacity of PVT will be lower. Ultimately another device has to assist. Let's assume the electric element in the boiler. In case of heavy frost this is not more expensive than an air source pump, but a much more simple solution.

For earlier mentioned extreme situations it would be an option to connect to another water source, such as thermal energy storage system (WKO) or a geothermal basket. In that case for the lengths of the summer the surplus of heat can be stocked  and be used in wintertime so that the water source heat pump can run on low energy. Best practise learns one doesn't need large storage capacity for months on end since the system intermediate heats up on every single sunny day. 

A new development is coming: 5 th generation district heating. This is a heating system on very low temperature, say 20 degrees and most ideal to connect with PVT. Lukewarm water as a source and kind of battery for the neighbourhood. In England, Sweden and Germany this is known as Ectogrid  Powered by E.ON

How all this is interconnected you can see in the schedule or watch on YouTube.