ENERGIANALYSE.DK

The character of local distributed energy systems is set to evolve from co-generation systems (electricity and heating) over trigeneration systems (electricity, heating, and cooling) to Quad-generation systems (electricity, heating, cooling, and liquid or gaseous fuels). Quad generation represents an integrated state-of-the-art distributed energy plant that may come to provide for all local residential, commercial, industrial energy demands, including transportation fuels. An innovative Quad-generation concept is presented with variations, an operational dispatch model is developed, optimized using mixed-integer linear programming techniques, and analyzed on an hourly basis with respect to techno-economic consequences, including energy balances, economic costs, CO2 emissions, and intermittency-friendliness. The paper shows how compression heat pumps and synthetic gas production may be integrated with existing natural gas cogeneration plants. The resulting Quad energy concept is based on 100% renewable energy in terms of local fuel consumption, eliminates CO2 emissions, and supports improved system integration for intermittent renewables and distributed generation. Optimal designs are presented for supporting cost-effective integration.

Economic lifecycle costs are currently not competitive at projected energy price and market variance levels.

Keywords: Quad generation, 100% renewable distributed energy systems, synthetic natural gas, large-scale dual-mode heat pumps, techno-economic optimization.