Optimization of Domestic-Size Renewable Energy System Designs Suitable for Cold Climate Regions

Abstract

Five different kinds of domestic-size renewable energy system configurations for very cold climate regions were investigated. From detailed numerical modeling and system simulations, it was found that the consumption of fuel oil for the auxiliary boiler in residentialtype households can almost be eliminated with a renewable energy system that incorporates photovoltaic panel arrays for electricity generation and two storage tanks: a well-insulated electric water storage tank that services the hot water loads, and a compact boiler/geothermal heat pump tank for room heating during very cold seasons. A reduction of Greenhouse Gas Emissions (GHG) of about 28% was achieved for this system compared to an equivalent conventional system. The near elimination of the use of fuel oil in this system makes it very promising for very cold climate regions in terms of energy savings because the running cost is not so dependent on the unstable nature of global oil prices.

Alaska's renewable energy potential.

“…RE sources can address both of these energy paths. A study published in 2006 1 investigated five domestic-size RE configurations for cold climate regions (research was conducted at Hokkaido, Japan). They found that for regions with a climate similar to Alaska's, a system that uses photovoltaic panels for electrical generation and a heating/hot-water system that has  a well-insulated electric water storage tank that services hot-water loads and  a compact boiler/geothermal heat pump tank for room heating during the cold season led to an ~28% reduction in greenhouse gas emissions.…”

Simulation and Feasibility Study on a 'Renewable Energy House' with a Geothermal Heat Pump-Powered Floor Heating System in Cold Climate Regions

“…An estimation of the annual energy balance (total heat losses from house = thermal demand for room heating) is needed for the evaluations of the system running costs and the Green House Gas (GHG: CO 2 ) emissions. Details of the annual simulation technique were based on our two previous works (3), (4) . Only two representative days -the clearest and the cloudiest days which are defined by daily energy sum of solar radiations -during each season of the year are used for annual energy balance estimations.…”

“…Figures 14 and 16 show the compressor input power, the GHP thermal output and the COP during the two days respectively. For the model house, the GHP operation must be switched off for two hours (4PM ~ 5PM and 6PM ~ 7PM) every day because of the regulations in the contract for the use of the special electricity price menu ('Snow Melting' (4) ) for running the GHP unit. These periods of no-operation can be seen in Figs.…”

“…The authors had developed PV/thermal hybrid collectors to get maximum energy gain from solar radiation (2) . For cold climate regions, however, the use of thermal collectors is severely limited during cold seasons, due to excessive low ambient temperatures and minimal available solar radiation (3), (4) . In these regions, it is increasingly becoming more fashionable to harness and use geothermal energy, which source temperature is more stable and warmer in winter than the ambient temperature, for water heating.…”

“…In the previous work we proposed a very simple and highly accurate numerical simulation method which estimated annual energy balances of a renewable energy system with GHP and solar PV/thermal collectors (3) . Annual running costs and CO 2 emissions in several renewable energy systems including a GHP were evaluated using the simulation method and the optimum systems were proposed (4) . In this work, a renewable energy "Model House", situated in Kitami city, on the north-eastern part of Hokkaido, is examined and reported.…”