During November and December 1992 I visited several groups involved with renewable energy, most of them dealing with education. These groups and their work are described briefly in this report. The groups in Melbourne, Australia have come a long way with education in this field and we have a lot to learn from them. Government funding is needed for large scale work, but useful work can still be done at the community level with much smaller budgets.
Producing cost-competitive small and medium-sized solar cooling systems is currently a significant challenge. Due to system complexity, extensive engineering, design and equipment costs; the installation costs of solar thermal cooling systems are prohibitively high. In efforts to overcome these limitations, a novel sorption heat pump module has been developed and directly integrated into a solar thermal collector. The module comprises a fully encapsulated sorption tube containing hygroscopic salt sorbent and water as a refrigerant, sealed under vacuum with no moving parts. A 5.6m2 aperture area outdoor laboratory-scale system of sorption module integrated solar collectors was installed in Stockholm, Sweden and evaluated under constant re-cooling and chilled fluid return temperatures in order to assess collector performance. Measured average solar cooling COP was 0.19 with average cooling powers between 120 and 200 Wm-2 collector aperture area. It was observed that average collector cooling power is constant at daily insolation levels above 3.6 kWhm-2 with the cooling energy produced being proportional to solar insolation. For full evaluation of an integrated sorption collector solar heating and cooling system, under the umbrella of a European Union project for technological innovation, a 180 m2 large-scale demonstration system has been installed in Karlstad, Sweden. Results from the installation commissioned in summer 2014 with non-optimised control strategies showed average electrical COP of 10.6 and average cooling powers between 140 and 250 Wm-2 collector aperture area. Optimisation of control strategies, heat transfer fluid flows through the collectors and electrical COP will be carried out in autumn 2014.
Accounting for around 40% of the total final energy consumption, the building stock is an important area of focus on the way to reaching the energy goals set for the European Union. The relatively small share of new buildings makes renovation of existing buildings possibly the most feasible way of improving the overall energy performance of the building stock. This of course involves improvements on the climate shell, for example by additional insulation or change of window glazing, but also installation of new heating systems, to increase the energy efficiency and to fit the new heat load after renovation. In the choice of systems for heating, ventilation and air conditioning (HVAC), it is important to consider their performance for space heating as well as for domestic hot water (DHW), especially for a renovated house where the DHW share of the total heating consumption is larger. The present study treats the retrofitting of a generic single family house, which was defined as a reference building in a European energy renovation project. Three HVAC retrofitting options were compared from a techno-economic point of view: A) Air-to-water heat pump (AWHP) and mechanical ventilation with heat recovery (MVHR), B) Exhaust air heat pump (EAHP) with low-temperature ventilation radiators, and C) Gas boiler and ventilation with MVHR. The systems were simulated for houses with two levels of heating demand and four different locations: Stockholm, Gdansk, Stuttgart and London. They were then evaluated by means of life cycle cost (LCC) and primary energy consumption. Dynamic simulations were done in TRNSYS 17. In most cases, system C with gas boiler and MVHR was found to be the cheapest retrofitting option from a life cycle perspective. The advantage over the heat pump systems was particularly clear for a house in Germany, due to the large discrepancy between national prices of natural gas and electricity. In Sweden, where the price difference is much smaller, the heat pump systems had almost as low or even lower life cycle costs than the gas boiler system. Considering the limited availability of natural gas in Sweden, systems A and B would be the better options. From a primary energy point of view system A was the best option throughout, while system B often had the highest primary energy consumption. The limited capacity of the EAHP forced it to use more auxiliary heating than the other systems did, which lowered its COP. The AWHP managed the DHW load better due to a higher capacity, but had a lower COP than the EAHP in space heating mode. Systems A and C were notably favoured by the air heat recovery, which significantly reduced the heating demand. It was also seen that the DHW share of the total heating consumption was, as expected, larger for the house with the lower space heating demand. This confirms the supposition that it is important to include DHW in the study of HVAC systems for retrofitting. ; iNSPiRe
The iNSPiRe project addresses the need for energy efficiency measures by focussing on making so called deep renovations using multifunctional, industrialised kits in order to speed up the on-site installation process and reduce costs. Energy renovation investment is a multi-factor decision and many of these factors are not technical, which is why this report analyses the non-technical barriers to this investment decision. The study focusses on the kits developed within the iNSPiRe project, but many of the findings are relevant for other single stage deep renovation projects. Both the planning and implementation phases are considered. The aim was to develop suggestions for overcoming these non-technical barriers so that the iNSPiRe kits can more easily be deployed in the market. The report is based on a study of policy documents, the experiences of European umbrella organisations for architects, property owners and local governments as well as on a large number of in-depth interviews with relevant stakeholders. Many of the 60 participants were made in conjunction with stakeholder workshops that were organised for specific focus groups such as architects, private property owners, public procurers and the stakeholders of the European Housing Forum. The non-technical barriers have been split into economic, political and social barriers, with most interviewed stakeholders emphasising the economic aspects. Subsidies are considered by most as essential for property owners to take the decision to make a deep renovation, but stability of the subsidy programs is essential to have a good impact. Low-interest loans are not as favoured. Other key economic issues are the increase in the asset value of the property after such a renovation and the green value of the resulting low energy building. These are both difficult to quantify, partly due to the fact that such renovated buildings are not as yet so common, and vary in the different property markets. The EU has many policies on energy efficiency that are relevant for renovation of buildings, with the 2010 Energy Performance of Buildings Directive (EPBD recast) and the 2012 Energy Efficiency Directive (EED) being the most important. Many member states were late in implementing these and most have problems with forcing compliance with them. National tenancy laws can also make energy renovations difficult by restricting the possibility of raising rents for. For the iNSPiRe kits, regulations and standards are seen as a barrier in the short term as the kits combine several different functions into one product that are covered by several different regulations and/or standards. The social barriers are mostly concerned with the tenants, while architectural considerations are also important. In buildings with owner-occupied flats, the decision process for renovation is difficult and even more so when deep renovation is to be considered. In rental properties the owners and tenants have different interests and incentives, leading to possible conflicts. All have uncertainties about the use of multifunctional kits and how well they will perform technically as well as about how much they will save economically. The report makes a number of suggestions for overcoming these barriers. Especially important for the iNSPiRe kits is training of relevant installers and planners and use of Life Cycle Cost calculations to show the expected benefits over the lifetime of the products. In each section of the report, in addition to the analysis of the specific barrier, there are sections with specific comments from the interviewed stakeholders. ; iNSPiRe
