Solar Technology

We simulate the electric boiler, ASHP and GSHP heating technologies stand-alone as well as with each of the following solar technologies to find the optimal combination.

1. Photovoltaic (PV)
2. Evacuated Tube Solar Collector (with & without PV)
3. Flat Plate Solar Collector (with & without PV)
4. Photovoltaic-Thermal Hybrid

Click on any of the above technologies to learn more about them.

Photovoltaic Area

For the simulations that use photovoltaic panels, the simulator optimises the area of panels your home would require to achieve the lowest net present cost. It optimises the area of the panels to the nearest 2m², with the maximum area of panels its simulates being one quarter of your homes floor area. For simulations that also have a solar thermal technology, the maximum roof area is shared between technologies.

Solar Thermal Area

For the simulations that use a solar thermal technology (evacuated tube, flat plate of photovoltaic-thermal hybrid), the simulator optimises the area of technology that your home would require to achieve the lowest net present cost. It optimises the area of the technology to the nearest 2m², with the maximum area its simulates being one quarter of your homes floor area. For simulations that also have a photovoltaic technology, the maximum roof area is shared between technologies.

Thermal Energy Storage Volume

For the simulations that optimise the thermal energy storage volume (being the electric boiler, ASHP & GSHP) the simulator outputs the optimal size your home would need to achieve the lowest net present cost. If the thermal energy storage is too small to meet all demand during peak-electricity hours then the heating technology is forces to charge the TES during peak-electricity times. If the thermal energy storage is oversized then money is spent uncecessarily on a large water tank. The cost of a larger TES must be outweighed by the savings made by being able to charges the TES during off-peak electricity times.

Operational Expenditure

Operational expenditure refers to the amount of money spent yearly to run the heating system (fuel costs). Often to achieve low operational costs the upfront capital expenditure is high. However over the life time of the system (20 years) the saving of low operational costs may outweight high captial expenditure. For systems with photovoltaic panels, operational costs may even be negative (generate income) if the amount of electricity they produce exceeds your homes needs allowing you to sell excess generation back to the grid.

Captial Expenditure

Capital expenditure refers to the upfront cost / initial investment to purchase the heating technologies. Most renewable technologies, in particular Hydrogen Fuel Cells and GSHPs have a much higher capital expenditure compared to a conventional gas boiler.

However when combined with photovoltaic panels these technologies can achieve a lower net present cost due to very low or negative operational costs.

Net Present Cost

Net Present Cost (NPC) refers to the combined cost of the captial investment and operational expenditure over the lifetime of the system (20 years), accounting for inflation, which the simulator takes as 3.5%, the standard for UK HMRC.

Operational Emissions

For each system the simulator estimates the yearly operational emissions, in units of equivalent grams of carbon dioxide produced. A system's emissions can be negative if the system is generating electricity using photovolatic panels, which when sold back to the grid offsets emissions that it produces.

While the heating technologies may not produce emissions directly, they use electricity generated by the grid, which the simulator takes as 212gCO₂/kWh. The emissions of Hydrogen technologies is dependent on how the hydrogen was produced. Three sources are simulated:

1. Green: Hydrogen produced by electrolysis of water using grid electricity. As the grid decarbonises the emissions associated with Green hydrogen will decrease.
2. Grey: Hydrogen produced by combustion of natural gas, which releases carbon dioxide
3. Blue: Hydrogen produced by combustion of natural gas, but with Carbon Capture and Storage (CCS) to reduce the carbon emissions produced by the combustion of natural gas.