I've spent a little time with an individual lately who has had Enmax manage a solar power installation for him. Due to his prominent role in the renewable power industry, the commitment he shows by doing this outweighs the economics, which are at present, not the cheapest in cash cost over any period of time if you're making your decision on that basis. Andrew Leach has done a good writeup on the economics of this at current, saving me the need to duplicate my own, but his appear pretty on track with the spreadsheet I started creating over the last week.
The reality is, you'll pay a lease cost, generate probably about 20%, or maybe a little bit more, of your consumed power, be able to sell what you don't use back to the grid, and therefore continue to pay about 80% of your bill (that's a bit of a misnomer, since your bill doesn't fluctuate entirely linearly with consumption given transmission and hookup charges).
The economics probably mean you're donating a couple thousand dollars to some nether space of solar power over 15 years. Having said that, there are portions of this program I like. First, it's a single call to an established organization. They do the rest. You don't have to tinker with inverters, panels, permits, etc. This is good. This means when economics do come around, there'll be much much less barrier to a residential customer deciding to participate. They bill you monthly anyway, so swapping some of your bill to a lease payment makes it easy.
Which brings me to my second point - the way to actually save on energy costs currently is to use less. Now I don't know about others, but I'm not one of those people to sit in the dark, turn my fridge to some crummy setting that doesn't keep food for more than a couple days, turn the house temps to barely warm enough to keep me alive, etc. I want comfort and a normal behaviour pattern. Which is a longwinded way of saying that I expect most of my reduced power consumption to come from improvements in technology.
Lighting is a relatively small portion of a/my household's power consumption. 6% is the North American average, but the point of the below is you could get that to 1% in a few years... we're nearing the economics of the step change. I've tracked LED bulb pricing now for 4 years. These will generate equivalent spectrum and candlepower of light as my current bulbs, with 80% less juice. I bought one a year or so back to try it out. But it was economic at that time only if a) you used a high power price (ie. interestingly enough, still lower than I pay at retail in a deregulated, natural gas saturated market... hmm), b) a high usage rate, and/or c) put a high value on your time spent changing bulbs. One house is one thing... but when these become unquestionably economic by easily meeting all those economic hurdles, light isn't going to cost us nearly as much. On a national level that'll move the needle. The rough math is for GE/Phillips/Sylvania type brands, the 4 year trend for a single bulb at retail is approximately $50->$40->$33->$23. First, it's telling that the first years they were few sizes, more science and technology type retailers, and costly. Now they're Home Depot, Wal-mart, dimmable, warm or bright white, and on the verge of being truly economic. Second, as they become more widespread, I now can find wholesale, bulk and OEM better than previous, which means it looks like I can source 50 for $17 each... although I'd like to actually try those ones first/see them. Even if their light specs are stated, it helps to see before placing big orders.
What does that tell me? We're 1-2 years away likely from mass adoption when they get to the famous ending in 7 Wal-mart price of $9.97. You can buy 50, not change bulbs in your house for 25 years, and be better off without even recovering any salvage value for your existing bulbs (which I'm sure you can do on Kijiji). In Alberta, with our retail prices per kWh that are "shown" to be less than what the package economics read (they seem to use 11 cents), you might think this isn't worth it. Truth is the effective is higher than the cents per kWh your bill shows, as the "administration fee", "delivery charge", "distribution charge", "transmission charge", "balancing pool charges", "local access fees" and"rate riders" are all associated bs that generally scale with consumption - so you want to keep yours low if you can.
And what else does that mean? I've seen that the average North American home consumes 20,000kWh/year (Canadian stats seem to be more along the lines of 17,500kWh/year per person). Seems high as mine is about half that, but I'm not around a lot, have a small family, and an efficient house, and don't have TV's and use electricity for heat. Regardless, that average has lighting at 6% or 1,200kWh. But if you could actually trim that proportion inline with a per bulb LED efficiency, that takes you to 1% or about 180kWh/year to generate the same light. That's 5% of the "average household's" consumption. That helps. I think starting in 2 years and stretching out for 5 years, that transformation will happen for the most part. But I'd still suspect we're 5-10 years away from the improved yield from the sun in terms of panel technology, economies of scale in manufacture and installation, that make it more viable to pursue at Calgary's average annual sun volumes. Twice the powergen at half the cost and we'd all have them, but those are monumental changes. A key hint on progress will be when you see the thousands of acres of Wal-mart roof in North America twinkling with panels. When that time comes, the price insensitive, socially motivated pioneers will have your one call local utility warmed up to install them.
For those who are aggressively into "green" power, don't panic if you're in Canada. ~65% of Canada's electricity is produced from renewable sources (mostly hydro, but some wind). So we're already "green" without going nuts for the "green" movement without understanding the stats.