~90% power saving

[DamonHD]

Hi,

The first rule of moving power off-grid is to eliminate waste I think.

As it happens, yesterday at home all day (though on my own as it happens), less than 4kWh of mains electricity was used over a 24-hour period, compared to ~33kWh/day average for the previous quarter last year, thus nearly a 90% reduction in usage if this day proves anything like typical.

Now that 4kWh/day is just about do-able by solar PV in the UK in our local area (there's a practical limit of about 4kWp of RE that the local electricity distribution network will allow to be attached to one phase in a small domestic installation), and 4kWp should be able to generate 4kWh/day even on almost the darkest London winter days, so we could, with a grid-tie, be a net exporter most of the the year.

I'm not going to do it (yet) but becoming a net provider is a fun idea!

Rgds

Damon

[strider3700]

90% is very impressive.  I managed to drop 40%  fairly easily but beyond that I haven't found easy/inexpensive enough ways to remove the other major parts(electric hotwater).

Where did you find the best bang for the buck improvements?

[AbyssUnderground]

I don't know how much I'm saving with my measly 36w of PV (which acts like 15w most of the time) but I do run my laptop sometimes and always run my desk light on an evening (6w CCFL which would otherwise be 3x60w incandescents).

[DamonHD]

Hi,

Well, the biggie was replacing my rack of old servers at home (for my business) with one low-power laptop, since I was already using 3x the normal UK household's power on them alone, practically!  You'll have seen me twittering on about the laptop elsewhere here in my diary, etc.

But we've also been sure to trim on domestic things such as the washing machine and dishwasher and TV cable box and stereo, etc, when when not in use were eating >1kWh/day just staring at us...

It was also an eye-opener to discover that our old home WinME desktop PC is one of the most hungry things in the house if left on for a few hours per day at ~250W, followed by the fridge at 80W average and the TV at 60W (plus cable box at 20W).

We've replaced almost every remaining bulb in the house with CFL (most of them were done years ago anyway), which should save more than 1kWh/day at my estimate.  (We have one very expensive LED mains light too as a test, but we dislike the colour.)

The icing on the cake, though only significant after all the other savings have been made, and why I'm at this board, is that I'm taking maybe about another 250Wh/day (no missing 'k'!) of my office's consumption for lighting and computing off-grid with solar PV at the moment.  I may increase that to >400Wh/day by investing in a much larger PV system at significant expense, else the current system will only save maybe 80Wh per day in grid power mid-winter, which is clearly neither wallet- nor planet- saving!

Note that having mains natural gas to heat our water (and food) probably makes a huge difference to our costs since it's about 1/3rd the money per kWh compared with mains electricity, and probably better in efficiency/CO2 terms to burn that gas directly for heat rather than generating electricity and shipping it over long distances.

Rgds

Damon

[DamonHD]

Well, you're saving more or less 1kWh of mains for every 6 hours that you are not running those 3x60W incandescents.  The fact that you're not taking the remaining 3% from the mains, but instead using PV, is a bonus!

Someone elsewhere was having a go at me about the cost of transporting the panels and battery to me having used significant energy (ignoring that their own heavy van has a bigger battery that they shift every time they drive somewhere for example!), but I suspect that if you look after your PV and battery carefully and eke the maximum life out of it then you are probably ahead, so that last 6W is probably almost 'free' compared to mains electricity or an oil lamp or candles or whatever (ie you don't just give up and go to bed when the sun goes down).  Maybe we should do the lifecycle costs sometime.

Rgds

Damon

[gotwind2]

Damon.

I think you might get along with RossW in Oz - He certainly knows a considerable amount on this subject and is a nice guy in my experience.

He is a member on this forum, and self built his 'house on the hill' - well under it actually..

Maybe he will post a reply when he has a awoken

Ben.

[DamonHD]

Thanks Ben...

[TomW]

Not only is RossW a stellar guy but he is known to hang out on IRC regularly but due to time difference its usually late at night. He seems willing to help most of the time and he knows his stuff. All in all, not bad for an Aussie.

Just a heads up.

Cheers.

TomW

[scottsAI]

Hello Damon,

Energy is energy, be it electrical or gas.

The best bang for the buck is solar hot water. Not solar electric!

Have fun,

Scott.

[DamonHD]

Agreed.

But stopping wasting ~30kWh/day of any sort of energy is a good start, yes?

Rgds

Damon

[scottsAI]

Hello Damon,

:-) YES. Great reduction in energy use.

I have a SEIT farm, shut down for the summer, 71% reduction in cooling cost. Bad enough to pay for running them, then pay even more to cool!

I myself would like to build something like this:

http://www.solar-solar.com/Attachments/PICT5.jpg

Figured I would mention hot water has a better return on investment. Not as cool maybe.

Have fun,

Scott.

[DamonHD]

I'd like the climate and direct sun and pool to go with that reflector!

You are definitely right that solar thermal is likely to be the best return on investment for most of us (once we've stopped wasting energy on standby gadgets and poor insulation, etc).

In my current situation however, I can't half-rip-out my boiler to fit solar heating, and we may move soon depending on family circumstances, and we don't have an unobstructed south-facing roof, so my PV pilot is the best (easily portable) thing I can do at this moment, plus maybe some toy wind power...  Besides, it's making me think, which is good!

Rgds

Damon

[scottsAI]

DamonHDm

Thinking is good. I like the trackers, high latitude good return for cost if DIY.

My project is a zero energy home design. Planed to build it this summer. My job situation may have changed. So on hold until I figure out what is going on.

Still working on the design. Keeps getting better!

Sounds like you had several servers, how did you replace it with one laptop?

Have fun,

Scott.

[DamonHD]

Simply by consolidating all the functions possible into one box.  Not too hard on *nix, but I had to simplify things somewhat, and discard lots of old cruft.

There are just a couple of things from the old setup not supported, like a public NTP server that was badly abused anyway.

But in practice *nix gives you enough facilities to pretend to be several different machines that it wasn't too hard.  Not even anything as flashy and fashionable as 'virtualisation', just things like inetd and virtual IP interfaces.

This is my general page about the set-up: http://www.earth.org.uk/low-power-laptop.html

I can answer more specific questions by email if you'd like, rather than bore everyone here.

Rgds

Damon

[Capt Slog]

Hi Damon,

It was also an eye-opener to discover that our old home WinME desktop PC is one of the most hungry things in the house if left on for a few hours per day at ~250W

I'm not sure, but I didn't think that a PC uses all of its PSU wattage all the time.

So when disc drives and suchlike are idle, the power consumption is down?

[DamonHD]

210W when doing nothing (screen on, desktop staring back at me), 250W when worked hard.

So, being under load does make a small difference, but not much.

Newer machines (and laptops especially) are better at avoiding waste doing nothing, but to see the difference being that small was astonishing!

Rgds

Damon

(I have a little Java app that helps with an AI project of mine, http://gallery.hd.org/_AI/remote.jsp and click on the download-and-run link if you want to join in, that, in the light of the above, aims to keep the CPU about 70% busy on the grounds that it probably hasn't bumped up the power usage that much but should be getting decent work done!)

[rossw]

LOL. I feel compelled to reply in a brusk, abrasive, arrogant way, just to show you all that I'm NOT a nice guy.... us aussies are NOT nice. We're a product of our evironment - man-eating crocodiles, lethal spiders and snakes, drop-bears, all those things your mothers warned you of!

Ben, my home is the house IN the hill, not ON the hill (well, I think I can make that claim given that the ceiling is over a metre below ground!)

Yes, I hang out in IRC - usually between the hours of 0600 to 2300 AEST (about 2000 to 1300 GMT, work that out wherever you are!). Pop in and find us.  irc.albury.net in #aussiere, or irc.anotherpower.com in #otherpower

R.

[DamonHD]

Hi,

I'm not an IRC/IM man myself, but thanks for saying hi here.

And it's not true: I know plenty of nice Aussies and Kiwis, so there!

Rgds

Damon