Make your own energy with Home Electricity Generating and Non-Exhaust Heat System “ENEFARM”

• enefarm
• energy
• renewable energy
• renewable hydrogen
• technology
• wind power

By JoelJul 24th, 2009

TOKYO GAS Co., Ltd.

“From Houses that Use Energy to Houses that Make It”

“Enefarm” is a home usage fuel battery system that uses hydrogen retrieved from Tokyo municipal gas to create electricity and hot water. So, just how environmentally effective is? Firstly, I will explain the Enefarm set-up, and I’d like you to think about its effect on the environment. Enefarm Set-up (1) Make Your Electricity and Hot Water at Home

Conventionally, the electricity that we use travels a great distance to our homes from a power station miles away. (Nuclear Power stations in particular are situated in the middle of nowhere) A lot of energy is lost in the process, and useable energy is just 37% of primary energy. Enefarm greatly reduces this distance through generating electricity at home. In addition, through co-generation it collects exhaust head given off during generation. As a result, 80% of energy of primary energy can be effectively used as electricity (33%) and heat (47%). Heat is used for hot water and floor heating.

TOKYO GAS Co.,Ltd.

TOKYO GAS Co.,Ltd.

Enefarm Set-up (2) Generating Electricity through Chemical Reaction of Hydrogen and Oxygen
Enefarm retrieves hydrogen from Tokyo municipal gas, and causes a chemical reaction with oxygen in the air with electricity generating fuel batteries.
Methane, the main component of Tokyo Gas is an extremely hydrogen-rich fossil fuel, with 4 hydrogen atoms for every 1 carbon atom.

TOKYO GAS Co.,Ltd.

TOKYO GAS Co.,Ltd.

However, Tokyo Gas also contains sulfur so that it a leak can be quickly detected by its pungent odor. In the process of making Hydrogen, in addition to CO2, a minute amount of sulfur oxide (SOx) is also created.
(Tokyo Gas intend to change the composition of sulfur additive in order to reduce sulfur content by half).

Enefarm Set-up (3) Visualization through Remote Control
The remote control panel displays in real-time the amount of electricity generated, hot water level, amount of power purchased, and volume of CO2 reduction. You can compare this month’s electricity consumption volume with last month.

TOKYO GAS Co.,Ltd.

Environmental Effects Expected of Enefarm, and Issues
The three systems mentioned above all contribute to increased energy usage rate, and decreased CO2 emission volume. (3) raises eco awareness and may also contribute to reduced C02 emission volumes in places outside the home. Presumably it is also good for children’s environmental education.
According to Tokyo Gas, assuming a typical household (Detached house, 4 residents, total floor space 150㎡) using one Enefarm unit for one year would reduce C02 emissions by approximately 1.5 tons. This volume of C02 equates to roughly the amount absorbed by roughly 3,300m2 of beech trees. This calculates out to roughly 7 months worth of the average carbon dioxide emissions of one normal household car.

What I want to stress here is that Enefarm does not amount to zero emissions. Because electricity is generated by a reverse electrolysis process in water, at the point of generation, the only other thing created apart from electricity and heat, is water. However, C02 is emitted in the process of extracting the necessary hydrogen from Tokyo Gas. Put simply, if the amount of electricity consumed increases, so too does the amount of C02. In this respect it differs from other energy source-using electricity generating systems such as solar or wind power generation.
There is one other element to bear in mind when considering the Eco influence of Enefarm. That is, the use of heat. The Eco-fundament of Enefarm is its use of exhaust heat. As outlined in set-up (1), if it wasn’t using exhaust heat, the energy usage rate of Enefarm would drop right down to 33%, and would waste a lot more energy than existing systems. This is why houses that use heat for baths, hot water radiators and floor heaters have a high energy saving rate, and low CO2 emissions. That said, if you increase heat usage too much and you end up using conventional systems for back up.

Cost Performance of Enefarm
Currently, one Enefarm unit costs approximately 3.5 million yen.
Fuel and cost bills will go down, and there is a special gas fee plan available for Enefarm users. Subsidiary aid from the government also applies. Despite this, redemption of costs at time of purchase is difficult.
Enefarm makes up for approximately 60% of electricity used in a home. When demand for electricity is high, it can be used in conjunction with existing systems. However, it is not possible to use heat created during power generation in other facilities.
Due to restrictions of the Electric Utility Industry Law, usage must be stopped during a power cut.
Enefarm still has scope for improvement if the potential of fuel batteries is to be realized to its full potential. I’m looking forward to the next breakthrough.

This article has been translated from the original Japanese post