Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



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.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.

Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




  1.  
    Hi Phil, try here:

    Posted By: WillInAberdeenGovt published a consultation on how much to do this with carrots (cheap charge) and how much with sticks (remotely switch off car chargers if the grid is about to collapse).

    https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/817107/electric-vehicle-smart-charging.pdf


    From page 12
    ”The current electricity system has been designed to meet a peak in
    demand between 17:00 and 20:30. For the rest of the day there can be large
    amounts of underused generation and network capacity. Generation during these
    off-peak periods is usually cleaner and cheaper. EVs can support the transition to
    a smarter energy system by, for example, charging overnight (during the off-peak)
    reducing the need for investment in infrastructure, but also provide power back to
    the grid. This makes it cheaper for people to charge and integrates EVs into the
    electricity system in an affordable way.'

    Edit: but yes indeed, electric transport and heating does imply that many more renewable GWh will be required. The 'smart' stuff is just about not requiring them all at the same time of day, it doesn't change the problem of how to generate them.
    •  
      CommentAuthordjh
    • CommentTimeMar 30th 2021
     
    Interesting thread on MSE, linking to an article on ThisIsMoney that claims smart meters are rented to electricity suppliers at a cost of up to 14p a day per meter.

    https://forums.moneysavingexpert.com/discussion/6255259/the-hidden-costs-of-a-free-smart-meter

    I'll be interested to learn what the truth is one day (2035? :devil: )
    • CommentAuthorCliff Pope
    • CommentTimeMar 31st 2021
     
    "The current electricity system has been designed to meet a peak in
    demand between 17:00 and 20:30. For the rest of the day there can be large
    amounts of underused generation and network capacity."

    "Has been designed" surely means it was designed based on the old pre-EV pre-electricity age?
    That was yesterday. Today everyone has very smart meters constantly searching for the cheapest period to use electricity. How can designers be so certain that the peak will still be from 5 to 8.30 pm in future?

    You can observe this effect simply by switching to an Economy 7 system. Our old peak usage period probably was from 5 till 8.30. But with economy 7 we put everything possible on a timer. Now 45% of our electricity is drawn from 3am. If we had electric cars and electric heating the percentage would be much higher.

    The pandemic has shown everyone the benefits of changed working hours. Pretty soon there won't be such a thing as the standard working day. It's classic le Chatelier's principle - apply pressure to a system in equilibrium and the point of equilibrium will change so as to offset the effects of the pressure.
    • CommentAuthortony
    • CommentTimeApr 1st 2021
     
    If people cared and were informed yes, but the DONT!
    • CommentAuthorMike1
    • CommentTimeApr 1st 2021 edited
     
    There's an interesting system in France under their equivalent scheme. The off-peak hours vary depending on where you live, spreading loads on the grid. Most places seem to get contiguous hours during the night, but in some areas it is (or was) split between night and day.

    In theory, dynamic pricing offers should be coming in this year. I'm not sure what the latest is, but the 10-year (compulsory) smart meter roll-out is nearing completion; it's expected to be 95% complete by the end of this year after a Covid delay.
    •  
      CommentAuthordjh
    • CommentTimeApr 1st 2021
     
    Posted By: Mike1There's an interesting system in France under their equivalent scheme. The off-peak hours vary depending on where you live, spreading loads on the grid.

    That's the same as here then.

    Most places seem to get contiguous hours during the night, but in some areas it is (or was) split between night and day.

    E7 guarantees 7 contiguous hours overnight. I believe that is simply a result of the technology involved originally. E10 does provide multiple intervals that can vary between suppliers and may involve two or three separate periods.

    Dynamic prices are already offered here by some suppliers. And smart meter rollout is thankfully voluntary.
  2.  
    Posted By: Cliff PopeThe pandemic has shown everyone the benefits of changed working hours. Pretty soon there won't be such a thing as the standard working day

    Absolutely! The old paradigm of 'off peak' being 'overnight' is ancient history now. The new 'off peak' is also during the late morning and the afternoon.

    Graph is from energystats, it shows electricity was as cheap at 2pm as at 2am this week.

    This means there would be spare capacity for people to charge their cars and heat their WFH kitchen tables in the afternoon as well as overnight. So long as the grid has capacity to cover the teatime peak, then there will be spare capacity during the off-peak for EVs and heatpumps, in the afternoon or overnight or whenever.

    Posted By: Cliff PopeIt's classic le Chatelier's principle - apply pressure to a system in equilibrium and the point of equilibrium will change so as to offset the effects of the pressure.

    Indeed! That's the whole purpose of a smart meter, to encourage people to move their demand to an off-peak period, *whenever that may be*. If in future, working habits or weather conditions mean the off-peak moves to Wednesday afternoons or Monday mornings, then smart tariffs will encourage people to move their demand accordingly, or to let their smart EV charger move it for them.

    Economy 7 can't keep up with moving the off-peak times every day, unfortunately.
      Ex0TxHFXMAA1kJs.png
    •  
      CommentAuthordjh
    • CommentTimeApr 1st 2021
     
    Posted By: WillInAberdeenEconomy 7 can't keep up with moving the off-peak times every day, unfortunately.

    Economy 7 can't even keep up with changing the times twice a year :bigsmile:

    It's always on GMT, all year round. I did hint/mention it was old technology.

    Suits us just fine for now :devil:
  3.  
    :bigsmile: I thought you were looking at heating your house at 3pm as required, on off-peak prices, rather than trying to heat it at 3am by an amount depending how sunny you forecast the next day to be?

    Certainly blows the idea of 'storage heaters' out of the water. Maybe makes small holes in the ideas of 'thermal mass' 'thermal store' and 'DHW cylinder'. Why store up heat for the whole of the next 24h, if the peak period is only 3h duration?
    •  
      CommentAuthordjh
    • CommentTimeApr 2nd 2021
     
    Posted By: WillInAberdeenI thought you were looking at heating your house at 3pm as required, on off-peak prices, rather than trying to heat it at 3am by an amount depending how sunny you forecast the next day to be?

    Yes I am - that's why I said 'for now' :bigsmile:

    Certainly blows the idea of 'storage heaters' out of the water. Maybe makes small holes in the ideas of 'thermal mass' 'thermal store' and 'DHW cylinder'. Why store up heat for the whole of the next 24h, if the peak period is only 3h duration?

    Not sure I entirely understand what you mean here about thermal mass et al? The thermal store is driven by the desire to capture PV output. I think thermal mass is generally desirable in conjunction with a lot of insulation - long time constants mean there's little point in worrying about optimising heating within the day. But I do agree that if the only expensive period is 3-4 hours it makes the prediction problem a lot more tractable.
  4.  
    Been offered a smart meter via our supplier, what's the concensus then?

    a) Go for it
    b) Waste of time
    • CommentAuthorMike1
    • CommentTimeApr 28th 2021
     
    Go for it.
    • CommentAuthorCWatters
    • CommentTimeApr 28th 2021
     
  5.  
    8k SMETS1 were installed in March, vs 177k SMETS2, so you'd be rather unlikely to be offered one.

    Half the existing SMETS1 meters have been migrated to the SMETS2 system, the rest planned this year.

    a) Go for it
    • CommentAuthorrevor
    • CommentTimeApr 29th 2021
     
    I resisted a SMETS 1 waited for SMETS 2 and then only had it installed just recently as was installing solar PV. Whilst that is not up and running yet (a few days away) I have found the 1/2 hourly information very enlightening which I can graphically view next day (I am with Octopus other providers my not be set up to give same level of data) So yes worth doing. But ensure you get a SMETS 2.
    •  
      CommentAuthordjh
    • CommentTimeApr 29th 2021
     
    Posted By: revorI have found the 1/2 hourly information very enlightening which I can graphically view next day

    I have an old-fashioned E7 meter and I have 10-second data I can look at for as long as I like. You don't need a smart meter to see usage data, just a logging system. No internet servers involved.
  6.  
    Some people have shelled out to buy logging systems like that, but it's rather a minority pursuit. (And some use internet servers for their data!)

    For the vast majority of people in UK, getting a free smartmeter is the first time they see how their usage varies over a day, and mentally link those peaks to the appliances they were using.
    • CommentAuthorjms452
    • CommentTimeApr 29th 2021
     
    Thinking of moving to a smart meter to take advantage of the 'outgoing agile' tariff:
    https://octopus.energy/outgoing/

    Pays a premium typically after 4pm and our PV is west facing...

    Anything I need to be aware of other than second generation smart meter?
    • CommentAuthorJamster
    • CommentTimeMay 19th 2021 edited
     
    Also getting an Octopus 2nd gen smart meter fitted on Friday. S facing PV already installed. No gas, ASAP for DHW and UFH. Very interested in what power usage might be 'offsetable' to overnight if dynamic charging is more available. The cost of making a house smart enough to automate the switch is more of a challenge I think for most of us.

    Separately, I've got ~4 yrs of 5-minute power use and PV-generation data to model usage patterns with so I must do that sometime and see how saved costs might stack up against a battery system.
    • CommentAuthortony
    • CommentTimeMay 19th 2021
     
    Smart house or energy use can be done using WiFi plugs or controllers. Time of use metering info can come from web
    • CommentAuthorrevor
    • CommentTimeMay 20th 2021
     
    @ Jamster. The decision to have battery or not is a difficult one. There are many factors as to what will benefit be. I have just installed one at same time as a 6Kwp solar array and has been running now for 20 days. In that time have used about 1Kwh per 4 days from the grid. The grid usage is made up of spikes when a load comes on as the inverter needs time to decide how much solar, usually all of it, and how much battery to use. I rarely use more than 20% (2kw) of the battery capacity when solar not producing this is due that all appliances are A or A+ rated and all lighting LED. Today it is overcast and raining but are producing 0.5 Kw at 9:00 am but our background use is about 0.3 Kw and the rest is going to battery and if we do not use too much of it the battery will be 100% by end of day. So far is working well for us and hoping that having the large array will be of great advantage in winter. At moment we are generating far more than we need but can't export until get a MPAN export number, Our decision to go battery was influenced by the fact we do suffer outages in bad weather and battery will supply limited loads during that period. At moment we are using 20% of the battery capacity which will increase during winter and may not be enough but there should be the opportunity to charge it from the grid at cheap period if needed. The battery distributor calculation of the cost of the electricity it over the lifetime of the battery is 12p Kwh so basically you are paying in advance at this price and all should be good if no service problems and costs arise. The cost of our total solar investment will return about 4.5% which is better than any savings account and also is contributing to the reduced demand on the grid in a small way as well as supplying it (free at moment)
    So factors will be size of array/size of battery, your appliances, lifestyle, willingness to change your routine to take advantage of sunny days etc.
    •  
      CommentAuthordjh
    • CommentTimeMay 20th 2021
     
    Posted By: revorOur decision to go battery was influenced by the fact we do suffer outages in bad weather and battery will supply limited loads during that period.

    Where are you and what type of battery do you have please? I'd like to have that functionality but haven't found anything suitable yet.
    • CommentAuthorowlman
    • CommentTimeMay 20th 2021
     
    I'm interested too revor, with 10 kW of solar that part of the equation may be OK, although our intended usage may make it a pointless exercise.
    • CommentAuthorJamster
    • CommentTimeMay 20th 2021
     
    Hi Tony,
    Posted By: tonySmart house or energy use can be done using WiFi plugs or controllers. Time of use metering info can come from web

    Can you or others recommend either suppliers or "how to" guides please?

    Revor,
    Posted By: revor@ Jamster. The decision to have battery or not is a difficult one. There are many factors as to what will benefit be. I have just installed one at same time as a 6Kwp solar array and has been running now for 20 days. In that time have used about 1Kwh per 4 days from the grid. The grid usage is made up of spikes when a load comes on as the inverter needs time to decide how much solar, usually all of it, and how much battery to use. I rarely use more than 20% (2kw) of the battery capacity when solar not producing this is due that all appliances are A or A+ rated and all lighting LED. Today it is overcast and raining but are producing 0.5 Kw at 9:00 am but our background use is about 0.3 Kw and the rest is going to battery and if we do not use too much of it the battery will be 100% by end of day. So far is working well for us and hoping that having the large array will be of great advantage in winter. At moment we are generating far more than we need but can't export until get a MPAN export number, Our decision to go battery was influenced by the fact we do suffer outages in bad weather and battery will supply limited loads during that period. At moment we are using 20% of the battery capacity which will increase during winter and may not be enough but there should be the opportunity to charge it from the grid at cheap period if needed. The battery distributor calculation of the cost of the electricity it over the lifetime of the battery is 12p Kwh so basically you are paying in advance at this price and all should be good if no service problems and costs arise. The cost of our total solar investment will return about 4.5% which is better than any savings account and also is contributing to the reduced demand on the grid in a small way as well as supplying it (free at moment)
    So factors will be size of array/size of battery, your appliances, lifestyle, willingness to change your routine to take advantage of sunny days etc.

    Thanks for your reply - how much electricity do you use? Did you have numbers before you went down this route? We're electric only so I have no doubt we'd use the majority of what we could store, and through the summer we'd generate more than enough excess to charge a 10kW battery. I'm less sure about the winter generation but equally with an agile tariff we'd be saving if we could buy at overnight / cheap rates. I need to do some numbers. When you did your costs - what is that based on? I'd be interested in doing the same and I have enough data to roughly model usage vs demand at 5-min intervals over the last few years. I've previously dabbled in this, guess I should get back on it.
    • CommentAuthorrevor
    • CommentTimeMay 20th 2021
     
    I'll try and answer all the points raised from my last posting.
    Am based in Anglesey close to the sea and v strong SW gales.
    Battery is 60 V 10 Kw, 186Ah BMZ ESS X German manufacture Korean cells. The battery use in outage is controlled by the hybrid inverter and power up is delayed by 30 secs and can power up to 20 amps. The clever bit is the inverter guess if you are adding to a current system you will need to gen up on how to add a battery to your inverter as mine Delios does the DC/AC and AC/DC inverting. So maybe inverter swap but think have read somewhere there are systems that you can add to your existing set up. If you go to this site they have a load of interesting stuff that you can gen up on which says how you can do it. There is a knowledge bank full of information

    https://www.spiritenergy.co.uk/

    We typically used about 10 to 12 Kwh per day in winter and 6 to 8 in summer. Since had system up and running we are showing 98 to 99% self sufficiency.
    Costing the ROI is what we will save on the electricity over the year and a guess factor for how much will make on export. I could have done it cheaper if gone for China made gear but I have v good reasons for avoiding them. The unknown is if we get equipment failures, warranties only cover parts they are usually a lot cheaper than labour, call outs, and travel costs. Unlike earlier FIT schemes you would not do it as an investment necessarily. I've done it because it felt the right thing to do.
    • CommentAuthorJamster
    • CommentTimeMay 24th 2021
     
    Thanks Revor - that's really interesting. Your usage is a lot lower than ours - that level of self-sufficiency is really good!
Add your comments

    Username Password
  • Format comments as
 
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press