By I. John Harvey,

Imagine Toronto Hydro (http://www.torontohydro.com/) sending you a cheque each month instead of a bill.

Or, perhaps, just getting a statement saying you owe nothing for the electricity you used in the last billing cycle.

Gordon Shields of Net Zero Home Coalition (netzeroenergyhome.ca) says it isn't a dream and could be reality with just a little help from various levels of government to boost the concept of in-home generated electricity.

"Net zero homes draw electricity from the grid when they need and feed the grid when they have no requirements," said Shields. "The result is a net-zero gain, in other words, a balance of zero energy bought from the grid."

In other words, what you've drawn from the grid you've replaced. Ergo, you owe nothing.

At first glance it sounds a more like fantasy than reality but the Net Zero Home coalition, formed in April 2004, insists it's a technically feasible concept.

Homes built using not just renewable energy technologies such as solar energy and ground source heat pumps but also design criteria such as passive solar heating can actually be self sufficient in energy, Shields said.

But yes, there's a snag. The big issue is cost and that's where the coalition wants governments to step up and nudge things along.

"We want the federal government to reduce the GST on the purchase of a new home incorporating the concepts," said Shields, with provinces also kicking back their respective sales taxes or levies.

That's because, like any new and developing technology, it's expensive and almost all that cost is at the front end of the process.

While many homes could benefit from retrofitting of renewable energy technologies, it's expensive and pay backs may take 25 years or more. And even then those retrofitted homes may never be wholly self-sufficient.

Solar Energy "Sexy"

However, said Shields, homes designed and built from the ground up with the goal of Net Zero performance in mind are feasible - with a little help.

The first step is to harness the passive energy (http://www.nmsea.org/Passive_Solar/Passive_Solar_Design.htm) of the sun, he said, designing a home so its windows take maximum benefit of solar radiation during the cold winter months with the ability to store that energy passively in water tanks or the walls and floors. In the summer, however, the windows would be shaded and shielded to prevent the searing heat from building up inside. Landscaping also plays a key role with the alignment of the home and placement of shade trees.

The most common technology then is thermal solar panels - roof panels that absorb the heat of the sun into a medium as water which is pumped through them and then stored in tanks -  heat pools and baths. They cost about $4,000, said Shields and are the cheapest and probably most developed renewable system.

From there on it gets pricey and more complicated - but like all renewable energies (http://energy.sourceguides.com/index.shtml) the prices are dropping as research and investments grow.

"Photo voltaic solar power is probably the most sexy of the renewable energy technologies but it's also among the most expensive," says Shields.

Photo voltaic technology - as the name suggests -  takes the sun's radiation and converts it to electricity. But it's not as efficient as say, wind turbines or other technologies such as hydro and it's expensive.

"Canada gets more sunshine that Japan or Euope and those are two places leading the way on solar," said Rob McMonagle executive director of the Canadian Solar Industries Association.

American home builders  (http://www.builtbypremier.com/P_Gardens/news_zeroenergy.html) in Caifornia are already selling net zero developments.

However, a Cambridge, Ontario company, Spheral Solar Power  (http://www.spheralsolar.com) which was been given a $29.5 million repayable grant by the federal government to develop it's technology, has made a breakthrough in both the design and production of solar panels.

It uses a thin flexible film sandwich to hold millions of tiny spheres of silicon in place which, when heated by the sun, react to generate electricity.

There are two other PV technologies in the market, one uses crystalline silicon wafers which are most efficient, converting about 15% of the sun's available energy to electricity, but also the most expensive. Thin film technology is cheaper but only operates at 7% efficiency meaning you need twice as much to generate the same power.

Ontario company on cutting edge

Spheral's technology though is about 10% to 12% efficient and can be mass produced fairly easily, making it much more cost effective.

"It doesn't sound like much but my understanding is a nuclear power plant runs at about 2% efficiency," notes McMongale.

The frontier now for Spheral is to continue to reduce the cost of manufacturing - and ultimately retail - while finding ways to integrate the film into building products such as siding and roofing. What gives Spheral the edge over other technologies is that its product can be several colours whereas the competition is limited to plain old black - and that esthetic advantage could be everything in the fashion conscious residential home market.

Which ever technology is used, developing those integrated materials with the 25-year warrantees demanded by margin-conscious builders, however, is one the  major hurdles facing the industry. A roof shingle with a built-in, scaleable solar panel may be technically feasible, but no one is going to buy unless it can handle Canadian winters and summers over the long run.

"Red River College in Winnipeg has a glass which has a tint in it that produces electricity (http://www.solarsolutions.ca/Architectural/RedRiver.html) and for large office buildings can lower their air conditioning costs," said McMonagle. "And there's another technology which uses three layers of paint to produce electricity (http://news.nationalgeographic.com/news/2005/01/0114_050114_solarplastic.html)."

And in a double whammy, consumers are going to balk if buying a Net Zero home is hundreds of thousands more than buying a regular home. Simply adding solar PV system to a home runs about $15,000 by the time you add-in the required batteries, inverters and controllers.

"You try to explain it in terms of a granite kitchen counter," said Shields. "Sure it's going to cost more, buy over the life of the product it will pay it back. And costs are dropping by about 5% a year as manufacturing gets more efficient."

The same applies with Net Zero homes, he said and the cost of even more expensive technology known as Ground Source Heat Pumps. These heat pumps recycle stored energy from the earth, cooling in summer and heating in winter.

The applied theory is that in winter, a few meters below the permafrost under the average home, there is enough heat to extract and bring back into the house for recycling as "found" energy. The system pumps a medium such as water or antifreeze through two sets of "radiators" one in the the house, the other underground.

Gets Expensive

 In summer the system works in reverse, taking excess heat generated by the sun through the radiator and sending it back through the medium into the earth where it dissipates and returns to help cool the home.

The big drawback is the price: Up to $20,000. With the average home consuming about 7,000 khw hours a year and electricity prices - with delivery, customer and other charges such as taxes included - it would mean power prices would have to double before such technology becomes attractive - unless the various levels of government subsidize the cost through tax elimination.

Ontario, for example, recently change metering rules to allow for hydro meters that run backwards when electricity is being fed into the grid. But more innovative incentives are needed, Shields said.

One of the issues is the rate at which power grid operators pay for power fed in by micro-contributors such as homeowners or small turbine operators. Fledgling green technologies can compete economically with nuclear generated power, for example, but are needed to offset dependence on other dirty and non-renewable sources such as coal or natural gas whose prices fluctuate with supply and demand issues.

In Germany, which is one of the biggest proponents of this, there's a tarffif applied to all electricity customers which is used to create a pool of cash to subsidize renewable sources feeding in the grid.

Eventually, proponents hope, the dependence on fossil and nuclear fuels can be eliminated and renewable energy will compete with hydro electricity.

For some, it's already paying off.

Toronto's Windshare (http://thetorontotimes.com/content/view/30/68/) project, for example, announced in January that 427 investors who collectively raised $800,000 to buy the initial 8,000 shares in the 750-kilowatt generator at the Canadian National will receive a dividend payment of $4 a share.

Ian Harvey
299 Warden Ave
Toronto On
M1N 3A3

416-699-6921
416-930-2149 m