Two of the most promising technologies for efficient use of fossil energy are the Combined Heat and Power plant (CHP) and the high performance heat pump. In The Netherlands, several small (micro) CHP plants are available for application in dwellings. In analogy to high efficiency boilers, a so called HRE quality mark is being introduced for units with a Primary Energy Ration (PER) of 140% or more.

Alternatively, state of the art heat pumps achieve a Seasonal Performance Factor (SPF) of 2.5-3 for DHW and 4-5 for space heating. Assuming an electrical efficiency of 50% in the electricity plant, this translates to a PER of 140% for DHW and 220% for space heating. Application of such a unit with a thermal output in the 2-5 kWth-range would save an additional 15-20 kWh/m2a in our terrace dwelling.

2. Summary

Table 2 below summarizes the effect of the different scenarios. The first scenario is the base case consisting of the Passive House concept plus a 3 m2 vacuum tube solar collector and a 150 l storage

vessel. Additionally, in case 2 domestic electricity is reduced by 39% using standby killers and A-label appliances. Here, innovative measures such as low energy coolers are not yet included. Most of the measures in scenario 2 fall under the first step of the Kyoto pyramid. The target of 75% reduction can be reached by adding 16 m2 of PV modules in optimum orientation.

In scenario 3, the area of the solar collector is increased from 3 to 8 m3 and the storage vessel from 0.15 to 0.6 m3. In this scenario, the target is nearly reached and only 4 m2 of PV are needed to reach it. Of academic interest is that a 16 m2 collector will reach the target without the need to install any PV.

Finally, replacing the boiler with a high efficiency heat pump will help reach the target without the need for additional PV cells.

5. Conclusion

A reduction of 75% of the total (primary) energy consumption in a Dutch terrace dwelling appears very well possible with an integral approach based on the Passive House concept in combination with a solar collector to maximise the amount of passive and active solar energy. In addition, standby killers and application of label A appliances are applied to substantially reduce the electricity consumption.

As a final touch, the application of either 4 m2 of PV cells or the application of a high efficiency heat pump will help reach the target. More innovative measures are being studied, but their effect is not included in these results.

The project is supported by SenterNovem in the EOS-LT framework (Energy Research Subsidy, Long Term).

References

[1] http://www. passiv. de

[2] Opstelten, I. et. Al (2007). Potentials for energy efficiency and renewable energy sources in The Netherlands, World Sustainable Energy Days, Florence.

[3] http://epp. eurostat. ec. europa. eu

[4] Basisonderzoek Elektriciteitsverbruik Kleinverbruikers (2000), EnergieNed

[5] W. Weiss et. al., Solar Heat Worldwide edition 2008, Solar Heating & Cooling programme,

International Energy Agency

[6] NEN 5128 Energieprestatie van woonfuncties en woongebouwen-Bepalingsmethode, ICS 91.120.10,

March 2004