|Cooma house temperatures and power thoughts
||[Feb. 1st, 2011|09:20 pm]
Got to say, I'm pretty impressed with how our house goes in the heat. On any of the warmer days, say 30+, the temperature inside will sit anywhere between 4-6 degrees lower on average. But on the really hot days, like yesterday when it reached 40, at one point we were 11.5 degrees cooler inside than it was outside.
On many of the hot days I'll actually leave two or three windows open around an inch. The house heats up a little more than it would, naturally, but it helps drop the internal humidity down by a fair whack, stopping the house from feeling as muggy.
In other news, our first power bill was $60. Given that we haven't had the solar panels up all that long, that's not too bad. Bill would have been about $330 without. That said, $30 of of bill was GST. Yes, they charged us GST on the full amount of the bill, then took off the money from the power buyback. I thought that was a bit cheeky.
As far as I can tell, our power usage appears to be about 75-80% the NSW average. Not too bad, and that's before we've swapped out lights for lower power ones. Mind you, beyond that I'm not sure how much more we can do. Most of the equipment is turned off at the power point, and is usually only on when it's being used. That said, I do want to get the stove top shifted over to gas, and at some point we may look into solar for water heating. We currently have electric water heating but the unit can be converted to work with solar as well.
Given the way power costs are going up in NSW, may well look at building a shed to house batteries, and getting additional panels set up to take us off the grid. But that'd be a fair way off, for all sorts of reasons.
Will be interested to see how our power bills look in the winter. Less sunlight, more lights on. Hopefully the fire will save us some cash, and the house will continue to show how good its insulation is.
Batteries in teh shed? Sounds like you're setting up for the apocalypse.
Or weening himself off reliance of government infrastructure.
I've seen a couple of sustainable houses that had their own battery banks.
Given how much electricity has been going up in NSW, and the fact that there are more rises set over the next couple of years, anything that cuts power bills is good.
Couple of recent things I found were people who had substantially cut their electricity usage and were still paying way more than they used to thanks to rises. I begrudge paying the bastards that charge people more for reducing their power usage. And some companies have started charging people who have solar cells more for any electricity they have to buy. I knew about this before we got the panels, and figured with our already low power usage we'd still be better off. Plus while I haven't done the math on the environmental impact behind the construction and installation of solar cells, I'm hoping it will reduce our carbon footprint a bit.
I don't think ours is one of the companies that charges the increased premiums.
The math still holds up, generally. Particularly as the solar cells can reduce peak needs substantially, which means less need for power station infrastructure and lower cost on the transmission network infrastructure. Cost/enviro wise the most effective power I think is still wind, in Aus at least (where we have so little potential for hydro), but trying to do wind at the residential scale (i.e. individual household systems) is a bit problematic (urban areas tending to have chaotic and turbulent wind conditions). Solar PV doesn't have that problem so much, it doesn't make too much difference where the panels are so long as they're not shaded out. So you can put them right next to where your power's drawn with no reduction of power production.
Being that I'm experiencing my first really hot and humid Sydney summer in a new house, I'm looking for ways to cool it in an environmentally and economically friendly way.
Solar panels are something I'm looking at, as well as replacing the current stovetop with gas.
Are you renting? Probably a silly question given what you mentioned doing, but I'm being vague :)
Pyramid Power did our solar panels, and I was really happy with the service. They were good, their contractors were good, and while there were a couple of minor errors, they were very quick and professional when it came to fixing issues.
Upgrading old insulation is a good starting point. If I had the money, I'd be looking at double glazing. It's getting cheaper and is the norm in many other countries.
Because I'm home during the day, I keep half an eye on the outside/inside temperatures and humidity. So in the mornings I leave everything open until temp is close to even, in the afternoon/evening I keep the windows closed, and curtains drawn until the difference is 2-4 degrees, then open everything up.
The most recent issue of ReNew (the ATA's magazine) has a pretty comprehensive review of solar power - panels, contractors, issues, processes, rebates. It's a good read/resource if you're thinking of going that way.
Hot and humid is an awkward combination to get good cooling. I've started looking into solar thermal, which works well in hot+humid conditions, but such systems don't seem to be currently available at the residential end of things. (The idea of solar thermal is that you're using the sun's heat - not light - and it usually works by driving a desiccant cycle that can pull the water out of the air, reducing the uncomfortable humidity so that less actual cooling is needed.)
If you've got the option of putting in solar hot water, that will probably make a bit of difference to your power bills again. Solar hot water is one of the more reliable technologies as far as paying for itself goes. How much difference I don't know - haven't hunted up Cooma's insolation and climate details yet. But if you currently have a storage hot water system that is running on electric, then that will be chewing a fair bit of power that you can avoid using.
It's definitely worth shifting the hot water over before you (one day in the future) move off-grid, both for total power consumption and also for the instantaneous total power draw. The instantaneous draw is the limiting factor of most systems - how much you can have running at once - and it's quite possible to short an off-grid solar system by (e.g.) running a washing machine that heats its own water because the draw goes up too high. If your hot water is constantly taking up half your available draw, that means you can't run other things even though you have enough power in the batteries to do so.
(I may be telling you stuff you already know here, can't remember. Sorry!)
Hey, could be useful for others reading his posts so win there.
While I myself like the idea of solar panels etc. the fact that I live in a strata apartment makes it unlikely in the extreme that I'll get to put any up. On the plus side however I have insulation from everyone around me and the closest I've gotten to using space heating or cooling is a fan on Christmas day when my family was over. Once.
Water is instantaneous gas which is again probably the best I can get with my situation.
If you want to I can possibly do an NPV calculation for you on the economics of batteries etc. Though not during semester 1.
Most parts of our house are like an oven except for the lounge room /Jadzia's bedroom and even some days the aircon isn't cool enough and the fans do very little to cool the place .I don't get why do babies want to hang out in the hottest rooms ? Living not that far from the hills doesn't help either but at least we had a a bit rain recently but we so need alot more .