Zero Energy House in Japan: Actual results and future target. Isamu Ohta Misawa Homes Institute of Research & Development CO., LTD.

Transcription

1 Zero Energy House in Japan: Actual results and future target Isamu Ohta Misawa Homes Institute of Research & Development CO., LTD.

2 Energy consumption of Japanese houses Japanese government has announced in COP3 (The Third Session of the Conference of the Parties to the UN Framework Convention on Climate Change) to reduce greenhouse gas emission by 6% in 2010 as compared with that in This Kyoto protocol has become effective last year. Although the energy consumed in the residential sector is only 14% of the total consumption, the expansion rate is 3 times higher than the rate of the industrial sector. Since people want to live a better and comfortable life, energy consumption in the residential sector will become even higher. There are many subjects we have to solve to reduce energy consumption but we believe Zero Energy House will become a key word for A comfortable living with less energy. kwh Average Energy Consumption in Housing 14,000 12,000 10,000 8,000 6,000 4,000 2, Year Cooling Heating Lighting & others Hot Water

3 Definition of Zero Energy House A A house that consumes less energy than it produces in an annual base Annual Photovoltaic generation Annual Energy consumption 1.0

4 General idea to realize Zero Energy (1) Reinforce insulation performance of walls, ceilings, and windows. (2) Design the house with minimum surface area. (3) Design openings for better solar gain in winter and solar shading in summer. (4) Install so called Top runner equipments with highest efficiencies. (5) Design all the roof including north side with building materialized Photo Voltaic modules. (Total capacity around 10kWp)

5 Zero Energy House (Since 1999)

6 Zero Energy House (Since 1999) Total floor area: 147m 2 10,465 7,735 1 st Floor 2 nd Floor

7 Zero Energy House (Since 1998)

8 Thermal performance of Zero Energy House W/m 2 K 4 USA Heat Loss Coefficient Japan (Highest level) France UK Germany Zero Energy House Heating Degree Day (D )

9 High-efficient equipments for Zero Energy House Heat Pump Hot Water supply system Induction Cooking Heater Hot water supply Water supply Hot water tank Heat pump unit Heat Exchange Unit Evaporator Compressor System COP =3.0 Induction cooking heater *All metal type Gas cooking heater efficiency 80% efficiency 40% Bulb type fluorescent lamp Heat pump air conditioning system System COP =3.0~

10 Roof totally covered by photovoltaic modules Building materialized photovoltaic module Amount of generation of a system on single side of the roof depends on the direction of the roof. Aluminum Rail Roofing Total generation of a roof having system on both side of the roof do not depend on the direction. Total capacity : 10 kwp

11 Relation of energy consumption and PV generation 15,000 (kwh/year) 12,000 9,000 6,000 3,000 0 Air conditioning Hot water supply Cooking Lighting and others General House Energy Consumption 13,146kWh/year Energy supply fulfillment ratio 118% Zero Energy House Energy Consumption 7,907kWh/year Photo Voltaic generation Photo Voltaic Generation 9,369kWh/year

12 Actual result of monthly energy balance Built in Okayama pref. (Energy supply fulfillment ratio : 123%) kwh/month 1,200 1, ,000 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep kwh/year 12,000 10,000 8,000 6,000 4,000 2, ,000-4,000-6,000-8,000 PV generation Day time electricity from power company Night time electricity from power company

13 Actual result of monthly cost balance Built in Okayama pref. (Net earning 120,000 yen/year) yen/month 30,000 25,000 20,000 15,000 10,000 5, ,000-10,000-15,000 O ct Nov Dec Ja n Feb Mar Apr May Jun Jul Aug Sep kwh/year yen/year 250, , , ,000 50, , , ,000 PV generation Day time electricity from power company Night time electricity from power company

14 Life Cycle Energy (LCE) balance [Tokyo] LC E(kWh) 1,600,000 1,400,000 1,200,000 1,000, , , , ,000 0 一般仕様 ( 東京 ) General House Zero Energy House ゼロエネ仕様 ( 東京 ) 年数 Year from construction LCE balance may be brought to Zero in the future!

15 Key factors for future Zero Energy House Reinforce thermal performance Enhance Solar energy use Introduce environmentally adaptive building elements

16 Solar shading by blind type shutter

17 Heat exhaust chimney for summer

18 Roof window with reverse ceiling fan

19 Final remarks Concept of Zero Energy House is quite important not only for country having few natural resources like Japan, but also for any countries. Environmentally adaptive building design method will become a key technology for future Zero Energy Houses. Exchanging information among key countries in ANNEX 44 will bring innovative progress to housing industries in Japan.