Smart Thermal networks for cities

Transcription

1 Smart Thermal networks for cities Gian Vincenzo Fracastoro Energy Department, Politecnico di Torino

2 Total Energy supply in Europe (1940 Mtoe, 69% in cities) 2500 waste heat in end use 2000 waste heat in energy production 1500 Waste heat Waste heat transportation electricity heat 1000 other RES hydro nuclear Heat demand primary energy final consumption end use natural gas oil products coal

3 Some comments The final demand of heat (550 Mtoe) dominates the demand side in Europe. Most fuels are used for heat generation and large heat losses are due to power generation in the energy transformation sector The final electrical demand is less than half (250 Mtoe). Part of it is still heat & cold (heat pumps and chillers) Transportation is mechanical energy (72 Mtoe) produced by thermal and electrical engines. Large heat losses are associated to energy conversion in this sector The final customers pay in total 210 billion for the electricity delivered and 180 billion for the net heat obtained. This corresponds to 3,7 % of the total GDP. The final demand of heat is dominated by the supply of natural gas. Heat deliveries from district heating systems have only a market share of 6 %.

4 The heat demand space heating DHW industrial heat other

5 EHI - Heating Demand Index in Europe The new European heating index (EHI) in a contour map computed from information for 80 urban locations in Europe. The space heating demand is proportional to EHI. 100 = average European demand (about 160 kwh/m 2 ), or Amsterdam, Dublin, Wien, Sofia Total heat needed for space heating: 275 Mtoe

6 Industrial heat demand PJ Altogether, 8.7 EJ or 208 Mtoe

7 Heat demand for DHW lt/day As an average: 50 lt/day/person, altogether 1.5 EJ or 36.4 Mtoe average

8 Cooling Demand Index in Europe European cooling index (ECI) computed from information from 80 urban locations. The average space cooling demand should be proportional to this index. the map is not representative for all locations in each country, since the existing data grid consists of only 80 locations. 100 = average European conditions (Madrid, Lyon, Prague)

9 Some considerations arise In Europe there is still a lot of waste heat, especially from power plants, which could be used for satisfying the heating demand from buildings, and 400 million tons of CO 2 yearly could be saved The heating demand is reducing, thanks to National policies encouraging building retrofits in many member States The cooling demand is on the opposite rapidly increasing, leading to increasing electricity demand and reaching higher and higher peak loads in the hottest months Energy from renewable sources is increasing its market share and is envisaged to grow even more in the near future, according to the EU scheme, but (solar) heat is generally produced quite ineffectively.

10 production, kwh specific yield, kwh/m2 Solar PV vs solar thermal PV prod ST prod PV specific yield ST specific yield area, m2 0

11 New Thermal Energy Grids Should be at the service of more energy-efficient buildings Match the daily (peak shaving) and seasonal (district cooling) heating demand profile take advantage of local heat sources which under normal circumstances would have been wasted (waste heat) Let smart heat sources (CHP, μchp, ground- or water-coupled heat pumps, MSW, ) and renewable energy sources (solar thermal, biomass, geothermal ) in. Be integrated with other (electrical, gas, cooling ) networks In a word: it should become a Smart Thermal Energy Grid (STEG) changing a conventional district heating system to a flexible multiple source network in which heat is fed into the grid at different locations, stored and distributed in order to meet a controlled demand at any time.

12 Integrated grids Electricity, heat, cooling, and gas in one integrated system where surplus energy is always used (picture from Fortum)

13 Conclusion Electrical demand is growing but heat and cold demand is still important, and will continue to be, even if space heating will hopefully rapidly decrease. We can t squeeze all thermal uses Smart grids are usually being thought as being only electrical, but also heat can be distributed smartly. The fundamental idea is to have new district heating systems, collecting heat from any possible source: CHP plants, waste incineration, recovery of residual heat from industries, biomass, solar and geothermal heat... This input of secondary and renewable resources to district heating systems will replace fossil primary energy supply. Hence, it will reduce CO 2 emissions and increase security of supply. It will also foster the development of thermal RES (especially solar energy), which are finding a difficult way to develop as electrical ones.

14 Thank you!