Energy Analysis - Net Zero Source Energy Building
Our findings in order for the Visitor Centre to meet the target of Net Zero Source Energy Building are presented as below. These results were exported from MERIT software, where the demand-supply matching process was executed.
The bar chart displays the energy flows (in MWh) for each combination of the best four for the Net Zero Source Energy Building, one for each of our heating supply options. As shown at the legend below the actual energy demands of the Visitor Centre have been multiplied by 2.67, the Site to Source conversion factor, for a more clear understanding of the results.
Annual Graphs
The annual graphs of demand-supply matching for each of the above combinations, exported from MERIT software, are shown below:
18 PVs (4.5 kW) + 1 Wind Turbine (6 kW) + Electric Heaters:
In this case electrical demands are the highest, due to the energy-intensive electric heaters as the supply option. As a result of the greater number of PVs installed, energy exported is also increased.
24 PVs (6 kW) + 1 Wind Turbine (2.5 kW) + Biomass Bioler:
This is the supply mix with the lowest annual electrical demand profile, since heating demands are fully covered by wood pellets. This is why demand was considered to be constant throughout the year.
30 PVs (7.5 kW) + 1 Wind Turbine (2.5 kW) + ASHP:
Demands are considerably reduced throughout the year compared to the first combination due to the ASHP, yet they are the second highest among the four combinations presented. This combination has the highest demand/supply matching rate.
30 PVs (7.5 kW) + 1 Wind Turbine (2.5 kW) + GSHP:
Using a GSHP leads to overall reduced electrical demands over a year and consequently lower requirements for energy imports.
Our suggestion
After comparing the energy performance for each of the above selected supply mixes, the overall best combination to achieve a Net Zero Source Energy Building was selected. The criterion was the electricity generated on-site to cover the site electricity demand and at the same time be as close as possible to it.
According to this, our suggestion for achieving a Net Zero Source Energy Visitor Centre includes a 5 kW ASHP as a heating supply option, adding 12 PV panels to the existing PV array (18 PVs) resulting in a total of 7.5 kW together with a 2.5 kW wind turbine as electricity supply option.
This gives a total annual electricity generated on-site of 13.99 MWh to meet the annual site consumption of 5.1 MWh which corresponds to 13.62 MWh of primary energy demands.
10.05 MWh are exported annually to the grid while the annual electricity imports are reckoned at 1.23 MWh.
