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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

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    • CommentAuthortony
    • CommentTimeJan 16th 2008 edited
    There has been a lot of discussion about wind power recently with the main underlying concern being that there still needs to the maximum demand available via other means of generation.

    BUT WHAT IF I was prepared to use my washing machine only on windy days? or to adapt my usage depending on availability?

    It is possible for us now to buy green electricity from a meter that allows heavier use on windy days or times. The so called green companies need to get to grips with this idea and start marketing smart meters and appliances.

    Additionally they could also sell band rated supplies, i.e. lower rates on windy days and graduated rates on other days/times linked to supply.
    The technology is available so why isnt it being used?

    It could even be that it would pay me to store some of the cheapest ( or free? ) electricity for my own use when the rate is higher?

    Is there a willingness anywhere to change the way we buy or sell electricity, or to make lifestyle changes?
    • CommentAuthorandytk
    • CommentTimeJan 16th 2008
    The problem is, would you be prepared to have your washing machine cut out half way through the cycle and potentially not restart for some while? Not only that but hot water storage using wind brings the inevitable question of, how long does the tank wait for "green" power before resorting to "dirty" power to ensure hot water for the nightly/morning rush?

    No one is going to be impressed if they spend big money on green tech and then it lowers their standard of living. After all, I can lower my standard of living for free.....

    All that said, demand side technology is being looked at. The problem is that domestic demand really isn't the biggest single user.

    I reckon a great deal of peak load shaving would be prevented if there was a law that stated all offices/work buildings are lights+computers off by 5.00pm. I'd be willing to bet that a large amount of peak electricity demand is the doubling up office/commercial demand just as everyone gets home and switches on their lights, elec oven, kettle, elec hob etc to have dinner.

    Of course the above suggestion is completely ludicrous, it'd be far easier just to build enough gen set capacity.

    • CommentAuthorstephendv
    • CommentTimeJan 17th 2008
    The Danes are testing a system that will use huge cold storage facilities to buffer energy usage: http://www.treehugger.com/files/2007/02/night_wind_proj.php
    Some kind of variable rate metering would be a great idea. I've got one of little those electric meters now that tell you your consumption etc. If I had a meter than beeped when we went onto a higher tariff when the wind dropped, I'd be rushing round the house switching off all non-essentials and I'm sure I wouldn't be alone. I'm not sure I'd want appliances cutting out part way through cycles though. Given that we have reasonably accurate weather forecasting, it might be possible to send the peak and off-peak tariff periods and rates a day in advance to a display on the householders meter. That way appliance use can be planned around the cheap rate periods.

    We could do some of this now with off-peak electric electric. The washing machine and bread maker now go on over night on cheap rate (other appliances like dishwashers and tumble driers also often have timers) and I'm thinking about getting an electric slow cooker to run over night to make stews etc (not for my breakfast you understand... to go in the freezer for consumption at a later date). All helps to balance out demand and reduce the need to build new power stations.
    Before going over to a cheap rate tariff you need to look at the usage in the different time periods. When on cheap rate you will pay higher standing charge and higher peak usage than the flat rates.

    So using a spreadsheet, work out how much Kwhr you need to consume overnight and the savings made, and then compare this to the extra cost of daytime usage and increased charges. You can then work out how much you actually need to use overnight to still be in profit after the extra daytime has been paid.

    I haven’t done this for a while with whatever deals are around, but previously I was surprised how much I needed to use. Running the washing machine every night didn’t use enough to justify it. Most domestic hot water cylinders on gas/oil central heating have an immersion heater, but this is generally viewed as a back up. Is heating a cylinder of water on cheap rate elec, cheaper than doing so with oil/gas? Only if the pence per unit elec is cheaper than the pence per Kwhr from oil or gas.

    Oil is 44p/lit at the moment so at say 80% boiler efficiency that’s 5.5p per Kwhr (44p/10KwHr per lit / 0.8), which is probably a bit more than cheap rate elec, but not much. The breakeven is about 35p/lit. Not sure about gas as I don’t live in the “suburbs”. The problem is that although the cost of this is reduced, there has to be a similar reduction in daytime elec usage other wise the overall cost for all energy will go up due to the increased rate for daytime usage when cheap nigh time is used. It becomes quite a complicated scenario.

    It’ll be quite close, and that will be offset by increased daytime charges. This I suppose would suit the out all day commuter rather than the at home worker + kids

    Obviously one should endeavour to minimise energy usage, but reducing it to bare cost does allow comparison to be made.

    If it were me on my own I could probably adapt to suit, but it difficult to do so with family and kids, not because they don’t want to, but because of the outside influences on the schedules i.e. school etc etc

    Cheers, Mike up North
    • CommentAuthormzthomps
    • CommentTimeJan 17th 2008
    By monitoring for subtle changes of voltage frequency it is possible to identify when demand on the grid is exceeding supply. By fitting this technology into plugs on certain devices in the home it would be possible to reduce demand whenever this event occured. Fridge freezers would be a good application.

    This is pretty much the same principle as used by National Grid to manage demand on a constant basis.
    • CommentTimeJan 18th 2008
    Posted By: tonyThere has been a lot of discussion about wind power recently with the main underlying concern being that there still needs to the maximum demand available via other means of generation.
    Have your own PV as well, for a start - that'll do a lot to even out your supply.
    • CommentAuthortony
    • CommentTimeJan 18th 2008
    I was talking about their supply not mine.
    • CommentAuthorGBP-Keith
    • CommentTimeJan 18th 2008 edited
    To be offgrid or anywhere near it you have to undergo a radical rethink of how you use energy and live day to day. Doing this can actually give you a better standard of living but make you unpopular with your friends and family as you can become an energy bore.

    It certainly makes these awful wet and windy days more tolerable though. On days like these (just as on sunny days) I look to do energy intensive jobs like making bread, washing or a having a cook-in. yes our cooker is electric (or wood on doldrum days). Fridges and freezers and washing machines are not appliances that can be turned on or off depending on voltage but cookers and toasters are.

    Lifestyle changes (most of the recommendations below will actually improve your health also):
    Do less washing
    Take less baths
    Travel less
    Have a family party every time the wind blows or the sun comes out (if you have the technology).
    Eat less food
    Chop wood with an axe
    Insulate you house to the extreme and open windows at every sensible opportunity.
    • CommentAuthortony
    • CommentTimeJan 18th 2008
    This whole area of making lifestyle changes is very interesting. May be we need a separate thread on it?

    It is nice to hear positive comments about making these from you Keith. Some others have been a bit negative ( the just leave me alone to switch it on mob )

    It might not be all that long before we dont have a choice.
    • CommentAuthorEd Davies
    • CommentTimeFeb 1st 2008
    "Fridges and freezers ... are not appliances that can be turned on or off depending on voltage"

    Clearly you can't let the fridge or freezer get too warm but suppose you had a suitable phase change material (PCM) in the freezer with a melting point around -20°C then when electricity is easily available you set the thermostat to -22°C but when your electrons are a bit more sluggish you wop the thermostat setting up to -18°C. There would be a long delay before the thermostat cut in as the PCM melted absorbing heat. With any luck the electrons would liven up again by themselves before you have to get them to do any serious refrigeration.

    I suggested this idea on a mailing list with the thought of using vegetable oil as the PCM. Somebody else suggested saline solution - appropriately calibrated to the temperature required.
    • CommentAuthortony
    • CommentTimeFeb 1st 2008
    Freezers take quite a long time to warm up on their own but the phase change idea is sound. Why not patent it and start selling it?
    Of course, ice is the ideal phase change material. Would work well for a fridge, less well for a freezer - unless it's a salt solution which handily freezes at -18C. In the long run, it's probably better to have more insulation since any PCM material just evens out the peaks and troughs in electrical availability. Insulation would do the same - especially as the heat capacity of the stuff in the freeze will likely be much larger than the thermal inertia stored in the PCM.

    Paul in Montreal.
    • CommentTimeFeb 2nd 2008
    It would be quite trivial to add a small circuit to most 24/7 appliances that monitored the grid frequency and switched off whenever it dropped below 50Hz (which happens when the grid is heavily loaded). It would work fine for fridges/freezers as long as there were enough guaranteed hours per day when it would be above 50Hz and the appliances were then allowed to run.
    • CommentAuthordickster
    • CommentTimeFeb 21st 2008
    Wandering off a bit, but maybe of interest. Shopping done twice monthly, 6 pint cartons of milk packed into freezer. Carton out of freezer into top of fridge to defrost over 2-3 days and (presumably) saving fridge juice usage rather than letting milk defrost in kitchen.
    • CommentAuthorstroudy
    • CommentTimeFeb 18th 2009
    Demand for Wind is a project being run by Durham University, Econnect and Good Energy with the aim of autonomously controlling domestic demand to meet wind conditions. Their website has loads of interesting data from live experiments. Get involved at http://demandforwind.co.uk/
    Posted By: dicksterShopping done twice monthly, 6 pint cartons of milk packed into freezer. Carton out of freezer into top of fridge to defrost over 2-3 days and (presumably) saving fridge juice usage rather than letting milk defrost in kitchen.
    Except you had to expend some juice in the first place to freeze the milk so there's no nett saving assuming the both the fridge and freezer are inside the heated envelope of your house.

    Paul in Montreal.
    • CommentAuthorSimonH
    • CommentTimeFeb 19th 2009
    <blockquote><cite>Posted By: stroudy</cite>Demand for Wind is a project being run by Durham University, Econnect and Good Energy with the aim of autonomously controlling domestic demand to meet wind conditions. Their website has loads of interesting data from live experiments. Get involved at<a href="http://demandforwind.co.uk/" rel="nofollow">http://demandforwind.co.uk/</a></blockquote>

    I was about to mention that - I signed up and am now the proud owner of a box of wires and remote "washing machine switcher onner". Only problem is you need to leave a PC on 24x7 to run it all - doh! I stuck it on a laptop but gave up when the wife complained she could hear the fan running at night. So they only get irregular data from me when the laptop is on.

    However it does show what is possible. You get a minute by minute trace of your electric consumption - overlayed with wind power available. You can set the remote switch device to come on when there's a surplus of wind overnight, with a latest start time say 5:00 so you still get the benefit of E7.

    Offices are a huge waste - I'm an IT contractor so move jobs frequently and am sick to death of seeing people leave PC's on over night, lighting on overnight. I'm doing some posters for where I'm working now (where they're particularly bad) as I've worked out a PC left on 24x7 uses 4 time more energy than it needs to and emits as much CO2 in a year as a car doing 2,000 miles. The worst was my last job, about 8 kW of lighting regularly left on over night! It because no one takes ownership, the staff think security will turn it off, but they are security for the main building - they don't have access to the individual office! One company owns the building, another runs the facilities, we occupied it, but it's paid for by the client. Who's going to pay to stick in automated lighting? No one. If I could have found out who paid the electric bill I worked out they'd save £1,800 a year and get payback in 2 years from a DALI system I'd priced up. But I've left now. Still bothers me though, as in this particular case our taxes pay for this building.
    • CommentAuthordave45
    • CommentTimeFeb 19th 2009
    Hi Stroudy

    I am one of the participants in the Demand for Wind project... The monitoring kit is a bit clunky at present (science lab stuff based on xPL if that means anything to you). It allows you to control your washing machine (or whatever) via a "ByeBye Standby" device. You can set it to trigger on overnight if there is a surplus of wind (according to DFW) or at the latest by a time you set. It works, but its a bit of a pain to set up.

    Going back to an earlier comment on freezers... I read a while ago on one that was mains-frequency sensitive. It worked on the theory that if electricity demand is high then the mains frequency drops ever-so slightly. This is detected by the fridge and it suppresses the thermostat switching on the compressor until the frequency rises again or the temperature drops too far for safety. AIRI the debate was about who would pay for this technology if it cost extra?

    Plenty of ideas around...
    • CommentAuthormaureen55
    • CommentTimeApr 20th 2009 edited
    What about using the wind-powered Biorock sewage treatment plant?

    Much greener than a septic tank and uses wind, not electricity. No turbines and it works on still days as well as windy ones.
    • CommentAuthorDdraigGoch
    • CommentTimeJul 26th 2009
    I've often wondered about the electricity cost of a septic tank. We have one and there's no electricity involved in any way so we're fortunate.

    We changed our lifestyle fairly drastically [for us!] and the electricity usage dropped like a stone. We pay about £35/month and lately we're getting money back:smile: The main change has been not using the electric stove, switching off lights and just not using them if at all possible, ensuring that anything we buy is as highly rated as we can afford, and that's about it. We don't use electricity for heating, apart from individual room heaters in the depths of winter - and we wear a lot of fleece between October and the end of May :smile:

    I'd be happy to put the washing machine, fridge or freezer on demand led usage, probably the television as well - but not my computer, I'm lost without the net ..... :shamed:
    • CommentAuthorListysDad
    • CommentTimeSep 24th 2009
    Well my two penneth. It is possible to reduce teh running cost sof PCs too. Donkeys years ago I used to install a system called Econolight. It was designed to reduce the running costs of flori tubes. When you turned the ccts on it started at 230v after some small time delay it switched the voltage down (using a transformer) to something like 190v. Whilst there was a slight lost of light from the tubes (apparently approx 10%) one quickly adapted and started saving money.

    We were asked to put this system in to a company who had hundreds of PCs. So we rang IBM and asked if their PCs could cope with a supply down at 190v. The answer came back, unsurprisingly, "no not possible would invalidate warranties etc etc". So, I called them again and asked teh same question a different way. I said I wanted to ship some PCs to Africa and asked if they would be ok operating where supplies oft drop to 190v. The salesman checked and said it would be fine... Moral of the story, is that ALL PCs are capable of running these days down to 90VAC as they have universal power supplies.
    • CommentAuthorwookey
    • CommentTimeSep 25th 2009
    Changing the input voltage to a switch mode power supply doesn't change the power consumption significantly. That's kind of the point.
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