Thursday, October 28, 2010

Sun power for eco-farm

At  Mur Crusto farm, we have completed the final part of the eco jigsaw: we have a photovoltaic system installed and up and running. After a glitch with the wiring, the very professional MGS got our system operational last week. Below are some photos of the installation. Click on them for full sized views:
 Above are the two arrays of nine Schuco panels on the roof. They are supported by a heavily-galvanised robust steel rail system and connected electrically in series so as to generate anything up to 600 volts DC on a good sunny day. The output power is connected to a massive box, the inverter (see below).
 The inverter and its associated safety switches mounted on the board below it, is really the 'brains' of the system, transforming a variable DC input into AC at the voltage and frequency required to feed it into the National Grid or to power appliances in the house. The small white box on the upper right of the board below the inverter records exactly how many kilowatt-hours of power are generated. Our electricity supply company Ecotricity needs to know the total in order to pay us for the power we have generated. With the new feed-in tariffs, this amounts to 41.3 pence per kilowatt-hour. The power is pumped into the Grid via an armoured underground cable which connects to the meter box of Gwyndy, our holiday cottage, which will now be rendered carbon-negative and so can be truly claimed (as we do!) to be an eco-cottage.
Above is one of the simple but rather clever displays on the inverter which tells us how much power is being generated. You can move backwards from Today to Yesterday to the Week or Month and see all the aggregated totals. These include the amount of money generated - always good to know! - and the number of kilograms of CO2 saved by this particular solar powered installation; the feel-good factor.

Are we now carbon-neutral? I don't know but we've
  1. insulated everything we can in Gwyndy and Mur Crusto farmhouse
  2. have one economical car
  3. installed wood-burning stoves for both buildings with all wood sourced from the farm
  4. built a solar heat collecting conservatory
  5. installed an energy-saving air source heat pump
  6. installed the PV system I've described in this post
I think that's about all we can do...

System details
  • maximum power the system can generate under ideal conditions - 3.78kWpeak 
  • expected generation per year - 2900kW
  • saving in CO2 over 1 year - 1.6 tonnes
  • system is based on 18  Schuco MPE 215 PS 05 polycrystalline, photovoltaic panels
    mounted on the south facing roof of the barn
  • the solar panels are covered by a 25 year manufacturer’s performance guarantee
  • total cost - 16,550 GB pounds
  • return on invested capital - 8.7 percent in first year rising incrementally to 15 percent in 25 years. Unlike the stock market, this investment payback is guaranteed and in any case generates far more than money held in a bank savings account
  • payback time about 10 years
  • annual income from sale of power generated - about 1,500 GB pounds

Wednesday, May 12, 2010

Heat pump: it's all go

Our heat pump is installed, commissioned and running beautifully. Goodbye oil. Hello clean, non-polluting, efficient heat energy. Yes I know most electric power is generated by highly polluting coal power stations but we source our power from a 'green' electric supplier and, later this summer, we'll be starting the process of finding and installing a photovoltaic solar generating system to more than cover the power demands imposed by the air source heat pump.

The installation of all the new radiators and pipework, replacing an ancient and incomplete system, went as smoothly as it could do. The 'dynamic duo' of Paul Southworth and his partner Clare (Paul is a plumber and electrical engineer) made the whole installation as painless for us as it could be given the scale of the job. And Paul's neat pipework and wiring in of the new highly insulated 210 litre hot water tank is a work of art (see photo).

There was one problem after the initial commissioning: the system ran fine but wouldn't turn off. But Ice Energy were quick to send an excellent engineer who quickly realised the problem - a simple wiring error not picked up in the first commissioning - and had the system running perfectly within 15 minutes.

So we are the happy owners of an entirely new concept in home heating which has the added benefit of attracting payments from the Renewable Heat Incentive from April 2011. The pump is very quiet and  amply copes with all the demands put on it. For the first time in the ten years we've been here we can be properly warm in any room in the house. Coupled in with the passive solar heating we get from the conservatory we built 3 years ago, we now have a warm, energy-efficient house.

Sunday, April 25, 2010

Going downhill fast: the Co-op in north Wales

An open letter to the Co-operative Group 
I've been a Co-op supporter for many years. I have a Smile bank account and my phone is with the Phone Co-op. I approve of the ethical stance of the group and seek out the Co-op for food wherever I can.
But now, I can't. First, the Co-op in Porthmadog closed, several years ago. Now the Co-op in Pwllheli, after going down hill for years, has closed. The formerly excellent Co-op in Menai Bridge has become Waitrose. Where is the vibrant Co-op community which we're always hearing about in the Re:Act magazine? It seems to have died in my part of Wales. I know where the Co-op is alive and well: Scotland. I have been consistently impressed by the stores in places like Oban and Ullapool and even in remote outer islands like North Uist (Solas Co-op). Why the difference?
All we are left with in my area is the Somerfield store in Pwllheli which is even worse than the old Co-op... unless you just want junk food, junk musak belting out of speakers everywhere you go and don't give a fig for Fair Trade or organic or fresh local produce. I am disgusted by this downgrade of the Co-op principles and am going to try shopping in Lidl or Asda. Yet perhaps you can reassure me that things will improve? My checklist for a decent food supermarket is
  • it should stock a good range of Fair Trade products and promote them proudly
  • it should stock a good range of organic produce
  • local produce like cheese should be readily available (Spar in Pwllheli has always managed this whilst the former Co-op never stocked local produce, despite regular requests)
  • there should be NO background music. Other much larger supermarkets don't have it and the grotesque assumption that everyone likes fourth rate pop music is wrong. Those who like music constantly have their MP3 players to listen to their choice of music. The junk music the Somerfield Co-op is off-putting to many potential customers. (I have conducted a small survey on this.)

My wife and I run a small organic vegbox scheme. We have around 30 customers who have all, when asked, bemoaned the disappearance of the Co-ops in our area. There IS a demand for a decent Co-op store which, rather than dumbing down like the appalling Somerfield, is proud to promote ethical issues and abandons the ridiculous notion that loud music soothes customers.
It would be pleasing to have a reply which actually attempts to address each of these points rather than the usual anodyne cut and paste of a standard letter. Please, Co-op, be co-operative!

Best wishes

Bry Lynas

Tuesday, February 16, 2010

Pumping heat

Great incentive:  It's unusual to feel that the government is doing something right but with the Renewable Heat Incentive, they certainly seem to be heading in the right direction in so far as encouraging renewable heat sources are concerned.

Heat pumps away!  Suddenly heat pumps seem a very sensible investment with the proposed incentives of about 7.5 pence returned to the householder per kilowatt hour of electricity expended to power them. So we're going for an 8.5kW Ecodan air source heat pump supplied by Ice Energy.We ordered the pump a few days ago and the first tranche of bits and pieces - the hot water storage tank and various other control devices to be installed by a plumber - are due to arrive later this week. Then it's up to us to modify the antiquated house heating system, currently powered by oil, so that it is ready for the actual installation and commissioning of the pump itself. We've found a plumber who is reputed to be very good and who has actual experience of air source heat pumps. He's paying us a preliminary visit tomorrow during which we can decide what we need to do and what we perhaps ought to do. Because the output water temperature of the ASHP is lower than that of an oil boiler, some radiators may need to be changed to a larger size.

The long road: So this is another step along the long and difficult road to carbon neutrality. The pump does, of course, use electricity but its coefficient of performance is around 3 (depending on the outside air temperature). That means we get 3kW of heat for every 1kW of electricity used. It becomes carbon neutral if we either buy our electricity from a supplier like Good Energy or generate some of it ourselves. We've rejected the wind turbine option for the obvious reason of lack of wind so we're now looking seriously at photovoltaics. The British government are offering major incentives in the form of feed-in tariffs which for us would 'generate' 41.3 pence for every kilowatt hour our PV array generates, either for us or which is fed into the national grid. It is really beginning to make sense to invest money in these technologies... much safer than stock markets.

Saturday, December 05, 2009

All change on renewables

In my October post, I gave the impression that the case for the wind turbine was all cut and dried. It wasn't, as it turned out, and was a lesson to me on accepting real data as real. I had very much wanted a turbine for two reasons: 1. when the wind blows strongly, it's generally the time you need energy; 2. our location in NW Wales should have been pretty good for windiness. This latter assumption was strongly backed up by the two national databases of wind speed averages and predicted power output. The latter, as it turns out, was wildly optimistic.

NIMBY neighbours do us a favour: We had a tense meeting with our downwind neighbours, arranged to test the waters before formally applying for planning permission. They were implacably opposed to anything visible or audible and I found myself having a little sympathy with their views such that we agreed to go back to the drawing board and see if there were alternative sites or just alternatives. So, Val and I had another look at the results for the average wind speed yielded by the anemometry; the real data. I had previously suspected the anemometer of under-recording wind speeds and, with this in mind, we had checked its calibration by holding it out of the car window at different speeds on a calm day. It was spot on.

And the real average wind speed? I had two results from the anemometer read-outs. One was the average wind speed and the other was the average gust speed. I had - wrongly as it turned out - assumed that the true average would be the average of these two averages (the 5.1m/s figure I quoted in the earlier post). I was always worried about this assumption and had made efforts to find out the correct position, so I posted a question of Green Building Forum and Val phoned an anemometer company and discussed the issue with an expert. The upshot of Val's chat was that we should totally ignore gusts! So that means that the windspeed on my best exposed site in windy north Wales is a paltry 3.58m/s, averaged over almost 12 months! So a wind turbine is out for the best reason of all: there really isn't enough wind on this site. The anemometry and neighbours' complaints saved us from jumping to the conclusion, fostered by the databases I mentioned above, that windpower was for us. So we are saved from acrimonious disputes and almost inevitable planning rejection, from appeals and from building a 25k pound white elephant!

So we're now looking at photovoltaics for which no planning consent is needed. Feed in tariffs of around 36 pence/kWh make this a viable option.

The moral of this story: If you're thinking of putting up a turbine, do the anemometry and believe the results!

Tuesday, October 20, 2009

Planning for wind

This is a 6kW Proven turbine on a 15m mast, courtesy of Proven. The little girl is not one of my grandchildren!

I have just written to our local planning officer to find out how the land lies for a full planning application for our intended Proven 6kW turbine.

Why a wind turbine? As you may have read in earlier posts, we propose to install a small wind turbine on our farm in Llangybi, north west Wales. We have two reasons for wanting to undertake this project: firstly we feel we have to do what we can to help combat climate change and are already doing what we can. We have grandchildren and are concerned about the world they will inherit. In this windy area, a turbine is easily the most practical way for us to more than neutralise our carbon footprints. As we approach the critical United Nations Climate Change Conference in Copenhagen, our own government exhorts us all to take action (Act On CO2). This we want to do. Secondly, the turbine should generate a useful income (particularly with Feed In Tariffs) and thus become an additional diversification for our main farm business of growing vegetables in a co-operative for our local box scheme. Details of this environmentally friendly scheme are available on the Llangybi Organics website.

The Site: This is to be in the centre of our land, as far from neighbours as possible whilst consistent with being appropriate for turbine location. You can also view the site on a Google map (a pin marks the spot and the high-resolution satellite imagery shows the hedgerows clearly ).

Windspeed data: A viable average windspeed for microgeneration is generally taken as 5m/sec. How do we best know what our average windspeed actually is?

  • NOABL (BIS) database gives 5.3 - 5.6m/sec for 10m above ground level (agl) (grid squares SH4341 and 4241 in which the turbine will actually be located) and 6.1 - 6.3m/sec at 25m agl. Turbine hub height of 15m agl should receive an average of 5.7 - 5.8m/sec.
  • Carbon Trust Wind Yield Estimation Tool gives 6.0m/sec at 15m hub height with anticipated 13,885 kWh/y generation potential with corresponding CO2 saving of 7.456 tonnes/y
  • Anemometry from October 2008-October 2009 on exactly the planned site with anemometer 11m agl has given average wind (in a year with long periods of blocking anticyclones) at 5.1m/sec based on 147,331 data points. For a description of this, see my previous post. [By the way, this complete set of equipment is now for sale so if you're interested, let me know by way of a comment with your email address. This includes the data logger base station, anemometer and everything needed to connect to a PC including software and cables, the 11.5m mast and supporting gear. I have even calibrated the anemometer. About 100 pounds for the lot!]

Distance from neighbours

Cae Du (upwind for the prevailing southwesterlies) c.160m
Llwyn Helyg (downwind) c.200m
Brongybi (to west) completely shielded by intervening woodland

Turbine details: Proven 6kW on 15m mast (high enough to avoid turbulence from hedgerows and a serious reduction in performance). The installation will be about 60m from our house where it will be connected to the grid via an inverter. Its slow rotation speed and direct drive (no gearbox) means that this turbine is both reliable and the quietest on the market in its class (e.g. 45dBA at 5m/sec). The result is that noise from the turbine is reduced to the swish of the blades turning in the wind, virtually unnoticeable compared with


background sound. See and hear examples from our intended installer's website. And yes, we have been and stood underneath these turbines and they really don't make much noise. The more the wind blows, the more noise there is from the wind in the trees and hedges which tends to drown out the increased whooshing of the turbine.

We await the planner's views before we pay something like 300 pounds just to ask for permission. In this day and age, you'd think every small farm like ours would be encouraged by government to put up turbines. It may come as permitted development rules change and the urgency for tackling climate change finally sinks in.

Sunday, March 29, 2009

Earth Hour in Llangybi

Celebrating Earth Hour by candlelight with Spanish wine and olives, Llangybi-style! Yes, we celebrated Earth Hour on Saturday night. I previously had thought it pointless but the WWF-inspired campaign has gone from strength to strength this year.

So even if it didn't help cause a dip in energy demand (signalling a 'vote' for low-carbon alternatives), it was somehow good to be sitting in front of our logburner with only its flames for light plus that of a beeswax candle. We thought of all the other thousands of people around the world who were doing the same thing at 8.30pm, from time zone to timezone as the planet rotated. There was a sense of solidarity and connectedness and, yes, voting for an end to the Age of Stupid fossil foolishness!

By the way, we used a beeswax candle because paraffin wax candles are made from oil products and we have to be purist about this, don't we! The carbon-neutral logs are from the farm with not even 1 wheelbarrow mile on them. Kosher, eh? Smug, no.