I’ve just borrowed the Taunton Home series of books from my brother. Each book in the series is made for someone who plans to renovate a different part of their house or property.

The first book we’re going through is the “New Bathroom Idea Book“. Unlike the Susanka books we discussed previously, we didn’t see any rooms in the book that we found wholly pleasing. Instead we could only pick out bits and pieces of each room that we liked, but this is really almost as helpful.

The book also contains technical information that is quite valuable, for example:

“Bathroom fans are rated according to the volume of air they can move in cubic feet per minute (cfm) and by their noise level (in sones). A small 5 ft. by 9 ft. bathroom requires a fan capable of moving 50 cfm, while larger bathrooms may need a 90-cfm or 150-cfm fan. Steer clear of fans that have sone ratings higher than 3; they’re too loud.”

At $28 each, the books are quite expensive but worthwhile if you can borrow them from your local library… or brother.

The helpful folks at SESCI have pointed me to a web site that details the rebates available for those putting solar power onto the grid.

For each kilowatt-hour generated, the producer will be paid 42 cents. That rate is “set for the entire 20-year length of the contract.”

Since we only pay 10.3 cents to take the energy off the grid, that sounds like solar panels would be a LOT more affordable; even profitable! However, there are a few catches.

For example, “new contracts will be subject to review every 2 years,” which sounds a whole lot like the guaranteed term for the $0.42/kwh offer is 2 years, not 20. Additionally, to put power onto the grid, we would have to pay an $800 initial fee AND $800 per year. (There are efforts under way to reduce or eliminate this fee, but that’s how it is today.)

If we assume that energy costs will increase at a rate of 5% per year, and we will always use 4200kwh/year (for simplicity) our energy costs over 25 years will be $28,189.53 from Toronto Hydro, or $35,806.78 from Bullfrog Power. (This latter number isn’t quite fair since presumably wind power will not become more expensive to produce over time.)

Solar Panels come with the previously mentioned up front cost of $25,000 and we are assuming the cost of borrowing that money is 5%. We also have an up front cost of $800 to be a power generator and must pay $800 per year to put power on the grid. (These costs should probably also increase at a rate of 5% per year, but we’ll leave flat for this example).

[Update 2007.11.03: It seems our (relatively low-light) region would require us to purchase a $50,000 solar panel array to cover our current electricity requirements. I have not updated the numbers below to reflect this amount.]

Even if we assume we are consistently paid 42 cents/kwh over 25 years for power we put onto the grid (though I think it’s more likely it would actually drop) and we assume we would be buying power back at the market rates from Toronto Hydro, our electricity expenses on a solar home would be $49,336.80.

So the ‘incentives’ that were missing from the previous calculation actually revealed the additional costs involved in putting power onto the grid. Solar panels would appear to be 38% more expensive than just buying clean power from Bullfrog.

I believe these numbers now factor in all financial incentives, and the projected increase in energy costs of 5% per year.

The government of Canada has an Office of Energy Efficiency (OEE) which, contrary to what you may have come to expect from your government, has a whole lot of truly helpful information to offer!

In particular, they have a library of consumer appliances, complete with their Energuide ratings. They also list available rebates, statistics, regulations, etc. The site doesn’t just deal with valuable information for energy conservation at home, but also for business and on the road.

Well worth a visit if you are concerned about your energy consumption!

I first became aware of the Stirling engine when reading about inventor Dean Kamen many years ago. He didn’t talk about the Stirling Engine in detail, but what I did find out was that it is an incredibly efficient non-combustion engine, that is powered by differences in temperature. (e.g. you can buy small a Stirling engine that is powered by the difference in the heat from your hand and the ambient temperature.

Sounds great right? In our home, maybe we could generate heat on the roof, and take cool from the ground and generate some free power, right? As is often the case, the first tip-off that there might be a problem with this logic is that nobody has done so already.

I did a little more research and it seems that unless you can get a heat differential of about 300 degrees Celsius, a Stirling engine practical for powering a typical home would itself need to be about the size of a typical home. Stirling engine size is proportional to the amount of power one needs, and inversely proportional to the heat differential between the cold and hot sides of the engine.

Another problem would seem to be the noise. The seemingly inappropriately named WhisperGen of New Zealand specializes in producing Stirling engine water-heater/power-generator combination units. According to their literature, these devices produce 63dBA of noise (and only a fraction of a house’s power requirements). While that’s quite quiet for a generator, it’s still the volume of a loud conversation, or air conditioner. That’s fine if one is encountering it from time to time, but to have it going in one’s home all the time would likely get a little grating.

It might very well be possible to overcome the heat differential limitation, but given the noise they generate it seems unlikely that Stirling Engines can be a part of any urban sustainable build.

Alex had mentioned that as a general guideline, energy prices are assumed to rise on average 5% per year, even though they’ve risen 7% per year in recent years. I actually find it hard to believe this would be the case over a 25 year period. This would mean energy costs would be over 3x more expensive than they are today (without factoring in inflation) by 2031.

As energy prices rise, the viability of various technologies to make energy generation more efficient rises. But if we do assume this number is correct that just removes the interest portion from our calculation and results in a monthly cost for solar panels of $83.39, which is still more expensive than simply buying the power from Bullfrog.

This advantage might disappear if there were financial incentives offered for providing solar power to the grid, but so far I’ve been unsuccessful at finding any. I had heard that the price paid for adding power to the grid was significant, but have also heard from someone else that those incentives are no longer available.

In addition, when those subsidies were offered, there was no commitment as to their term. An incentive that can be withdrawn at any moment is not much of an incentive at all. I’ll have to investigate further.

Our fifth design meeting continued to refine the garret and the access to it. It now includes an area which will be open to the ground floor and should act as a large chimney to allow hot air to rise and vent out, in the summer. We decided a curved, narrow but fixed staircase would be the best way to access the garret (instead of a pull-down staircase that would be less stable). The area will also include a narrow walkway through open ‘chimney’ to get to the attic space at the front of the house.

I took this opportunity to discuss my previous ideas about the economics of solar panels with Alex. He had read the article and suggested I’ve messed up the math in a couple of ways:

1. I didn’t include the usual 5% rise in energy costs (5% is used even though energy costs have actually averaged 7% in recent years).
2. There was no allowance given for the financial incentives offered by the utilities.

I’ll continue the discussion of these factors in the follow-up to the solar panel post.

When I was chatting with one of our neighbours yesterday I found out some interesting hearsay history of our property. Apparently he was talking with another neighbour who’s father built the houses a few doors down from us, and her Dad told her that a river used to pass through the area where our house is now, and there is quite possibly still an underground river there.

We’ve passed this information on to Alex, of course, who is now factoring in the possible need for specialized drainage for the property, and extra insulation around the foundation.

No word yet as to whether we’ll need a geotechnical survey to confirm this.

There’s an interesting video on YouTube about a new(ish) style of wind turbine called an AeroTurbine. It was developed by Bill Becker from the University of Illinois and has some tremendous advantages over traditional wind power generation.

In particular, his turbine doesn’t require a constant wind source; It works just fine with gusts of wind, as are common in urban settings. Also, this type of turbine cannot be spun too fast, whereas horizontal-axis turbines need to be shut down in high winds. AeroTurbines apparently run much quieter than H-axis wind turbines (though I’ve personally stood right beside a wind turbine and couldn’t hear a thing).

They are hoping to promote AeroTecture amongst architects to better capture wind with these devices in newly constructed buildings.

Unfortunately, no projected cost information is available at this time.

As mentioned previously, we aren’t going to be able to afford solar panels for our house, initially. We are planning space and wiring for them, and are confident solar technology will become quite affordable within a decade. Unfortunately, even our smallish appetite for 350kWh/mo. can only currently be sated by a $25,000 photovotaic array (factoring in the amount of sun we’d receive in Toronto).

But considering 350kWh/mo. only costs $49.22¹ from Toronto Hydro, I decided to run the numbers on the approximate cost of ownership for solar panels and was very surprised at the result. The disruptive force in the calculations was Bullfrog Power.

Even though I’ve skewed the numbers in support of buying solar panels, that option is still 60% more expensive, for no real benefit to the environment (considering one can buy clean power from Bullfrog).

When I first thought about writing this entry, it was supposed to be about the revolution of distributed power generation that will come with low-cost, high-efficiency solar panels. But now that I’ve run the numbers I don’t see that happening.

A relatively small power generation company like Bullfrog can already sell green power at very reasonable prices. Given the overhead involved in managing one’s own power generation, Bullfrog are in a much better position to take advantage of changes in technology than individual consumers are. When prices drop for individuals, they’ll drop even more for Bullfrog, and other power generation companies.

In fact, companies are just the sorts of long-lived entities that thrive on long term capital investments such as solar panels… when there is actually any profit in it. The fact that no power-generation company is generating with solar (at least not around here) leads me to believe that buying solar panels for home power generation is terrible investment (financially and environmentally). For those living anywhere near an urbanized area, it seems likely there will always be a company able to generate green power with the latest technology far more efficiently than any individual could.

Using solar water heaters in the home still seems like a good idea. (Water can’t be heated ‘cleanly’ by someone else and then piped into your house.) But this also raises a question: If heating our home or water via non-solar means, is it better to do it with less efficient but green electricity, or more efficient but dirtier natural gas? I will have to do a few more of these types of studies on the cost of solar water heaters for tap-water and radiant floor heating vs. electrical heaters.

At the moment, I’m thinking the answer might just be Bullfrog.

FOLLOW-UPS TO THIS POST ARE NOW AVAILABLE (Follow-up 1, Follow-up 2).

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Our fourth design meeting was really good.

The plans are quickly becoming solidified, but that didn’t stop us from making significant changes here and there. The small storage room at the top of the house wsa turned sideways, at Alex’s suggestion. It will now allow quite a bit of light into the main stairwell, and the room will not block the light from getting to solar panels on the south roof.

We had also sent Alex a variety of photos from our neighbourhood showing what style of houses we liked, and which we didn’t. This was definitely a big help in shaping the ‘face’ our house would have. Taking photos of interiors and exteriors that capture your interest will be extremely useful as you move through your design process.

I would really like to post some schematics to show everyone, but I’ve promised the architect I wouldn’t show unfinished work (which I can completely understand — I hate doing that, too). As such a lot of the discussion about why we chose to position everything where we did, will have to wait a few more weeks.