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  • Interesting article on renewable energy efficiency
  • aracer
    Free Member

    Specifically small scale PV. I suspect both sides of the debate will take this as supporting their view – personally the last few paragraphs pretty much confirm my pwn feelings on this http://www.resilience.org/stories/2012-09-19/blow-blow-pv-system-efficiency-case-study-storage

    Edukator
    Free Member

    Pump storage and technology to modify demand patterns are forgotten in that. The constant nature of nuclear production was dealt with, it will be no more difficult to deal with the intermittent nature of renewable production.

    The Italians already have a smart grid that turns on appliances remotely to mop up surpluses and switch off non-essential things during peak demand.

    wonnyj
    Free Member

    Bit irrelevant for 99.95% of the population as it’s about an extremely small offgrid system with battery.

    Normal systems feed back into the local grid if the electricity isn’t used.

    wonnyj
    Free Member

    And there is an awful lot of smart grid stuff happening here in the UK as well. Solar is the future!

    Onzadog
    Free Member

    Solar is not the future in the UK. However, a gird arrangement across Europe with wind from the UK, hydro from Scandinavia and solar from southern Europe might work.

    The investment needed in the UK distribution grid to make smart systems work is more than most people are willing to swallow on their energy bills.

    ninfan
    Free Member

    There’s rumours going round that the major power cut in Scotland this week was down to a sudden and unexpected drop in wind at a time when coal and gas backup generation had been spooled down.

    Edukator
    Free Member

    Except that the Italians using such a system save money, Onzadog. There’s a similar system in France but based on human intelligence. You sign a contract to benefit from a very low tarif all year if you pay a punitive tarif for a few periods of high demand of which you are notified. People organise themselves with other energy sources for those periods and save a lot.

    ampthill
    Full Member

    What I really want to know is how long a solar panel takes to produce enough energy to pay back the energy needed to make it.

    There are some really badly sighted panels round here and my gut instinct is that these may never offset the carbon used to make them

    aracer
    Free Member

    Are you serious? Just how many suitable locations do we have for pumped storage, how much can they actually store and how much does it cost?

    footflaps
    Full Member

    gas backup generation had been spooled down.

    Unlikely, one of the main advantages of gas is they can go from standby to full power in a few minutes. Coal takes hours to get the boilers up to full steam.

    Northwind
    Full Member

    ninfan – Member

    There’s rumours going round that the major power cut in Scotland this week was down to a sudden and unexpected drop in wind at a time when coal and gas backup generation had been spooled down.

    That’s fascinating, meanwhile the people actually investigating it say it was a distribution failure.

    molgrips
    Free Member

    The constant nature of nuclear production was dealt with, it will be no more difficult to deal with the intermittent nature of renewable production.

    How did you come to that conclusion?

    TooTall
    Free Member

    It isn’t a very good article. It’s a g33k showing off his ability to do some nalysis on his very rare off-grid system (which isn’t a very good design TBH). If he were really interested in making it more efficient there are a lot of things he could do that go beyond plotting scatter graphs. Lead acid is a good battery tech because it is cheap and easily recycled. There are better technologies coming that will answer grid storage way better.

    What I really want to know is how long a solar panel takes to produce enough energy to pay back the energy needed to make it.

    Probably less than 7 years in the UK – much less elsewhere:

    http://info.cat.org.uk/questions/pv/what-energy-and-carbon-payback-time-pv-panels-uk

    Edukator
    Free Member

    Working in the water industry and being aware of the number of existing reservoirs that could be used not only for water supply but also pump storage, and the number of existing hydro schemes that could be fitted with reversible pumps. Where there’s a will, there are a lot of potential sites, you only need a hill near a river. The Dinorwic and Ffestiniog ones you’re probably aware of but you don’t need such spectacular landscapes. for example

    TooTall
    Free Member

    you only need a hill near a river

    and a site with 2 reservoirs, which most hydro schemes I’ve seen don’t appear to be equipped with.

    Waderider
    Free Member

    I work as a consulting civil engineer building small scale hydro. The haven’t read any of the above, why would I!?

    UK National Grid Status

    Northwind
    Full Member

    Waderider, that is so ****ing cool.

    mikewsmith
    Free Member

    I know a couple of people here working on Smart grid stuff, part of the initial work is to get business users how to plan and operate stuff at the right time. The next step is to have a lot of stuff that can be spooled up automatically or remotely when excess power is available from peak renewables and make the most of it.

    But still stick with my main assertion that you need a good stable base load that kicks out 60-70% cleanly then build from there.

    TooTall
    Free Member

    part of the initial work is to get business users how to plan and operate stuff at the right time

    It’s amazing when you show people that good planning and processes will save them the most.
    I’m currently working with a guy who is doing off-grid CNC wood machining. His approach and methodology is the closest to perfect I’ve ever seen. Quite inspiring.

    mikewsmith
    Free Member

    yep apparently the local gym turns all their heating of when they close and then back on again in the morning with a huge spike, leaving it on low overnight eliminates that.

    Also making everyone turn computers off at the end of the day and then fire them up again between 8-9am.

    Edukator
    Free Member

    When you consider the part of the base load that comes from heating and A/C, insulating the housing stock and business premises is the first step. It’s currently 12°C outside, 21°C inside and I haven’t lit the wood burner (the only heating we have) since the last energy thread.

    Edit: it’s ten days since I used the immersion heater to top up the solar hot water and PV production is over double our electricity consumption at this time of year.

    ampthill
    Full Member

    The constant nature of nuclear production was dealt with, it will be no more difficult to deal with the intermittent nature of renewable production.

    How did you come to that conclusion?[/quote]

    Nuclear Power is I believe the slowest to bring on and off line. It takes days for the reactor to settle into a state where it has a stable nuclear reaction and power output. ( I had a really interesting chat with a man who worked in a nuclear power station while going round Dynorwic apparently its Xenon production that makes it hard to turn a nuclear reactor on and off) It is therefore not possible to balance a drop in wind by increasing nuclear power output. Coal isn’t much better

    Gas is a good technology to sit alongside renewable as its relatively fast to bring on and off line

    Smudger666
    Full Member

    Ampthill – it’s about a year.

    bigjim
    Full Member

    However, a gird arrangement across Europe with wind from the UK, hydro from Scandinavia and solar from southern Europe might work.

    Yep this is very likely to be the future, HVDC interconnectors are all the rage now and are essentially seen as an alternative to offshore wind development in a sense. Also add geothermal energy export from Iceland to your list too.

    there’s rumours going round that the major power cut in Scotland this week was down to a sudden and unexpected drop in wind at a time when coal and gas backup generation had been spooled down.

    Emphasis on rumours there I’d say.

    wonnyj
    Free Member

    Ampthill – the most recent study I saw (admittedly just a link on twitter) was to a German study and was about 2 years for a nice south facing system. You’re right though, systems facing north won’t payback well in either carbon or financial terms.

    That UK Nat Grid Status link from Waverider is cool. Shame it doesn’t include solar as we have in the region of 4.5GW of installed capacity today. However there is no central register of installed solar farms so the figure is based on internal industry estimates and out dated Ofgem data. Last week I saw this blog that indicates that this solar generation from this capacity is starting to impact on the grid.
    http://www.carboncommentary.com/2013/06/07/3090

    Here is a central european overview, looking at how german PV capacity is impacting negatively on conventional generation markets.
    http://www.renewablesinternational.net/baseload-takes-a-beating-over-weekend/150/537/78176

    mikewsmith
    Free Member

    Nuclear Power is I believe the slowest to bring on and off line.

    Hence it’s perfect as a base load generator, churn out 60+% of the power this way and use the rest as balance.

    samuri
    Free Member

    Working in the water industry…

    You’ll know then that most of the water companies are being approached to participate in smart grid technologies. Since water companies are largely the biggest users of electricity in the UK, it seemed an obvious step to talk to them to apply technologies to spin down non-essential pumping equipment to smooth out the grid under peak loads. Supermarkets and the waterways are also participating.

    Edukator
    Free Member

    They’ve been night pumping for years, Samuri, there’s a lot more to be done though in terms of reducing overall demand and in particular peak demand. Some progress in generation has been made, the Llyn Brianne dam frustrated me every time I sampled it but they finally started generating in 1996. For years water utilities just weren’t interested in the generation potential of their reservoirs. I’d love to see future schemes combining water supply, electricity generation and pump storage.

    molgrips
    Free Member

    Since water companies are largely the biggest users of electricity in the UK

    Really? What do they use it for? (genuine interest, not sarcasm or rhetoric 🙂 )

    Edukator
    Free Member

    Pumping out of aquifers/rivers, pumping through the distribution system (often through a network of small reservoirs which allow storage and overnight pumping, treatment, desalination. In world terms it’s a lot.

    UrbanHiker
    Free Member

    For those who love data…
    http://www.bmreports.com/bsp/bsp_home.htm
    …still doesn’t detail solar PV as far as i can see, but the graphs of generation by fuel type are worth looking at. Even gives Europe import/export etc.

    samuri
    Free Member

    In world terms it’s a lot.

    Aye, big pipe networks, lots of water and sewage to move about. And of course, any half decent sized treatment works will have thousands of pumps.

    But electricity costs money and that’s one reason why water companies will be eager to participate in energy saving schemes. I think our annual electricity bill is around £66 million off the top of my head and we’re one of the greener water companies.

    bigjim
    Full Member

    The new wtw for Edinburgh has turbines in the pipes, generates 25% for the site from one of them and there is another further down the system too. Bit of a no brainer when you think about it!

    samuri
    Free Member

    Aye, but shit is where the real value is.
    http://www.cambi.no/wip4/plant.epl?cat=10643&id=463527

    molgrips
    Free Member

    Molten salt is not new, is it?

    Edukator
    Free Member

    The problem with the privatised water industry is the lack of incentive from within to be efficient. They are almost always monopolies and inefficiencies are paid by captive customers. There was only one engineer in the office I worked in who was interested in anything vaguely innovative or investing for the long term. Thankfully European legislation has forced some investment because without that push I’m convinced the water companies would have just creamed profits off ever-ageing infrastructure to keep share holders happy.

    It’s an industry with a low appetite for risk bordering on paranoia. Look at the number of catchments that have ridiculous restrictions on the use of land in catchment areas and reservoirs. They don’t want people doing water sports on reservoirs claiming it would compromise water quality. Reservoirs with a high population of disease carrying animals in the water/catchment when the water goes through a treatment works that would happily deal with filthy water from a lowland river.

    Dual use whether for amenity or integrating energy generation goes against the corporate culture.

    ahwiles
    Free Member

    Edukator – Troll

    but you don’t need such spectacular landscapes. for example

    that example is in Germany; and it has a 270m ‘head’ – which is a lot; but it’s only 140MW (Dinorwig is 10 times the size)

    of course we could build more pump-storage systems in Britain, but there really aren’t many technically suitable sites (never mind sites that no-one would complain about).

    of course we’ll build more pump-storage, but it’ll be a massive job just to build 1 more ‘Dinorwig’ and we need a lot more than 1 more.

    maybe we could build them with the lower lake below ground level? – to increase the head available from our small hills.

    ?

    mrmonkfinger
    Free Member

    I read (somewhere, I forget where) an interesting (and fabulously non-technical) article where an american prof was proposing that we cast large concrete spheres, drop them like an anchor to some large depth undersea, and pump out water using wind. Then use the massive pressure difference to run a turbine during non-windy periods.

    the roundabout point being that pump storage doesn’t have to involve two reservoirs and a hill

    Edukator
    Free Member

    maybe we could build them with the lower lake below ground level? – to increase the head available from our small hills.

    Thames water already pour water into aquifers to top them up, generation while doing so is feasible.

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