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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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    • CommentAuthorGotanewlife
    • CommentTimeSep 9th 2014 edited
    Any thoughts on this bit of kit:http://www.navitron.org.uk/product_detail.php?proID=902&catID=67

    I have just changed tariffs and now pay 22p and 46p/Kwh - 17p is from 8pm until 7am plus hols and w/e - these are the headline rates, obviously being Italy it is well complicated... Anyway, I make about 6500Kwh/pa and use overall about 10% more than I make, and I use about 40% of what I make. Clear so far?

    In-laws have moved into an apartment on our ground floor this year and so neither they nor us have an overview of what's being used (one electricity system/meter). The idea of this tariff is that is designed for 'out all day workers' but it might work for us. Anyway the Watson thing: the idea is that us and them can see easily what's going on real-time with net availability shown by a green glow - so I would need 2 displays. They need a little education too and this might help (and if it doesn't we are effectively spying on them :devil:). But it is a lot of money, not that I can actually find the second display for sale anywhere on-line). So whatdoyathink - expensive rubbish, better alternatives, does it work, should I invest in one?

    I do have one concern and that is the wireless range as I have lots of solid stone walls and solid concrete beamed ceilings - repeater....increase cable length from sensors to sender????

    PS - not strictly relevant, but I get paid about them same for my exported electricity as I pay for off-peak so this is all about daytime usage.
    • CommentTimeSep 9th 2014
    I use the CurrentCost ENVI to display my usage, I also log it, but that is a different matter.

    The UK version allows two different prices to be put in, shows the instantaneous usage, the price, the previous days usage, the split between day, evening and night, the temperature where the receiver is and the time. It also calculates if you are using more or less than a previous period, what the usage was last week and last 30 days
    They do an 'optical' version that is very accurate.
    I find it very useful, and easy to understand. Just two figures to look at really, 'Energy Now' and 'Cost'.
    160 W as I type this and 53p for the day.
    • CommentAuthorGotanewlife
    • CommentTimeSep 9th 2014 edited
    Posted By: SteamyTea160 W as I type this and 53p for the day.
    Show off!

    Seriously though, the point is to display realtime what the PV is generating AND what we are currently using - the Watson then does the sum and glows green when there is excess PV elecy. Unless I read you post too quickly yours doesn't display both does it? The Watson does seem to have all the monitoring stuff as well, via a USB port, along with software etc - not so much of an interest to me at present but could be 'fun' in the future.
    • CommentTimeSep 9th 2014
    Posted By: Gotanewlifewhat the PV is generating AND what we are currently using
    Whoops, forgot that bit.
    Does it show 'which way' the current is flowing. I fitted a CC up to a community centre to monitor the usage, imports and exports. But that was because they were not getting FITS and the major load was on a single phase while the PV was split over the 3 phases. Was a rubbish installation.
    • CommentAuthorEd Davies
    • CommentTimeSep 9th 2014 edited
    Would this be an issue for you?:

    To self-fit the sensors, there needs to be access to either the live or neutral wire (single-core wires); if they are contained within a single big cable either side of the fusebox (consumer unit) then the sensors should be fitted professionally by a Solar Installer.
    Used a CurrentCost (similar wireless but on 8nn MHz rather than 433 MHz, IIRC) in a thick-walled stone cottage with the sensor in the metal roofed kitchen extension built outside the end gable and the display/computer connection at the other end of the house upstairs. Worked fine.

    Very confusing on the Navitron site that the “instructions” they link to are not for the basic product but for an add on kit to allow you to use two sensors to subtract the generation and import/export somehow.
    • CommentAuthorGotanewlife
    • CommentTimeSep 9th 2014 edited
    Posted By: SteamyTeaDoes it show 'which way' the current is flowing.
    Yes - as I mentioned it does the sum - ie takes what is being generated away from what is being used and then if what remains is positive it glows green - do keep up Steamy! I hoped the impossible to mis-understand glow would make if fool-proof for my in-laws......

    Ed looks like there is a version sold with 3m sensor cables so even were there to be problems I expect I could extend them a little further to find a sweet point. As for the cables - you are right there might be an issue as all the PV wires are in a tamper proof cable, terminating in security cable locked junction boxes but there are 2 solutions offered for the sensor set-up and I will check it them out with reference to my cabling. Anyway, no-one has said its a dumb idea yet so I might 'take it to the next level' - to use a Got To Dance obligatory comment.
    Gotanewlife - are you expecting the in laws to modify their lifestyle based on the glow of the green light from the box in the corner? - and will this last beyond the novelty period of the first month? - Don't put the kettle on for a cuppa dear, the green lights not on!!
    What would be the projected savings against the cost i.e. whats the ROI? Against just asking them not to put the washing machine on unless the sun is shining
    IMO the value will depend upon how willing you all are to manage your consumption by the green light on the box.
    • CommentAuthorEd Davies
    • CommentTimeSep 10th 2014
    I think not being able to get at a single live or neutral line would be a show stopper. Changing sensor setup won't help.
    • CommentTimeSep 10th 2014 edited
    Posted By: Gotanewlifedo keep up Steamy!
    I had been at work till late :sad:

    You may be better of getting old of the very cheapest energy monitor first, one that shows just the usage. See how the outlaws get on with it and if it make any difference.
    Or fit a sub meter and charge them :wink:
    Well I can get to the individual wires BUT they will need lengthening in order to fit the sensors - I also need to swap out the 30mA RCD and swap it for a 100mA RCD (it splits to 3 consumer units each with their own 30mA RCD) and my neighbour is an electrician so I expect I get him to do it....

    Meanwhile P-i-H, you have hit the nail on the head in terms of my worries - ROI. As it happens they have an electric oven (it was non-negotiable), and the oven, washing machine and dishwasher are the big ticket items - and yes it might help them but it would also help us because we don't know when they have the oven, dishwasher and washing machine on and they don't know when we have our stuff on. I am convinced it would really help but would it help nearly £200 worth: that is the question I am dithering on.

    With 2 washing machines, 2 dishwashers and 2 electric ovens (we have a gas one too and only use the electric one occasionally) in the house it doesn't take long to use more than we make.
    If you use 40% of what you generate then this leaves 60% to be paid for, plus the 10% under generation capacity. The 60% to be paid for is subsidized by the generation payment. Did I get this right?
    Do you know the split of the 60% to be paid for between peak and off peak. If there is more paid for during the day then it might be worth putting a timer on the dishwasher(s) and washing machine(s) to restrict their use to off peak.
    Another thought, if you got the gizzmos and saw the green light on - so quick start the washing machine - what happens when the green light goes out half way through the cycle. Do you carry on paying for the leccy or switch off until the green comes back on, either will cost! And do you have enough life energy to be ruled by little green lights?
    • CommentTimeSep 10th 2014
    How 'predicable' is your solar resource. Where I am it may be the highest in the country when measured by kWh/m^2, but it is very variable. Norfolk has a more reliable and predictable resource.

    It is odd as down here the two main renewable energy resources should be micro hydro and tidal, but we have wind and sun. Though wind is pretty good here, even though we have just had a couple of days without much (schools went back so the weather got better).
    • CommentAuthorGotanewlife
    • CommentTimeSep 14th 2014 edited
    Correct P-i-H though I get paid 15 cents/Kwh for my exported electricity making (under this new regime) a net saving of 7 cents/kWh by using my own electricity AND I get an incentive payment that almost covers my E33k loan over 15 years (paid for 20 so 5 free years!).

    About 20% of my usage is peak, dropping to 12 % for 4-6 months in the summer. I am going to put this on hold. I'll see how my bills pan out this year and go from there; meanwhile we'll instigate a general ban of avoidable loads during peak, given that, at worst, it will cost me 7 cents/kWh rather than risking 31c/kWh! Ta all
    • CommentAuthorrhamdu
    • CommentTimeSep 17th 2014
    Posted By: Peter_in_HungaryAnother thought, if you got the gizzmos and saw the green light on - so quick start the washing machine - what happens when the green light goes out half way through the cycle. Do you carry on paying for the leccy or switch off until the green comes back on, either will cost! And do you have enough life energy to be ruled by little green lights?

    We start our appliances when we see a big yellow light in the sky. That sometimes goes off again, too, but I'm afraid we don't interrupt a wash for every passing cloud.
    • CommentAuthorjms452
    • CommentTimeSep 17th 2014
    A benefit of the Wattson solar plus is that once you have one you can use it to run these at a fairly low incremental cost:

    Optiplug Intelligent Socket

    Not great for washing machines but good for (water) heaters.

    jms, now that is interesting; it would be perfect for my pool pump though it would have to go tandem with a timer - pool won't mind having a bit less filtering occasionally than programed for - I don't have a water heater, all solar here :cool:

    Shame it doesn't allow for an always on period and a rationed period each day, than things like freezers etc could be connected. Thinking about it I could plug such things in in parallel with the Optiplus...2 sockets one on a optiplug the other on a timer (on during off peak) - that way the freezer never gets less than 13 hours each day
    • CommentAuthorskyewright
    • CommentTimeSep 19th 2014
    Posted By: GotanewlifeShame it doesn't allow for an always on period and a rationed period each day, than things like freezers etc could be connected.

    If you fancy a bit of programming you can apparently do some very snazzy thing with Robin Emley's OpenEnergyMonitor based MK2i PV router.


    This guy on Navitrin was controlling 6 loads (& may now have moved up to 16!).

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