Turbotricity

We have decided to offer a 2.5kw turbine as a modest turbine that most people can afford, and which will make a meaningful dent in their energy bills

There are some cheap 5kw machines out there, but they are usually Chinese made and are simply not designed for our climate. At the other end of the scale, the 6Kw machines that are well made are costing about €32,000 installed. That is still more expensive per watt than our turbine.

However, there are other issues with larger turbines;

Planning Permission and Turbulence

The planning exemption for domestic turbines is a total height to the tip of the blade of 13m. With our rotor diameter of 3m, the tip of the blade is never less than 10m off the ground. This means that the blade tip is not exposed to turbulence at lower levels.

A 6kw turbine with a rotor diameter of 5.5m can only have a tower height of 10.25m. The blade at the bottom of its stroke will be 7.5m off the ground. This means that the blade tip (which does most of the work on a wind turbine) will suffer a lot more turbulence from surrounding hedgerows.

Effect of the new tariff

The new feed in tariff is set at 9c per KwHr for electricity exported, with a subsidy of 10c for the first 3,000KwHrs per year. Most of the extra power generated by a 5 or 6 kw machine will be exported at a price of 9c, whereas most of the power produced by a 2.5kw turbine will be either exported at 19c, or used by the householder at 16c.

The return on investment for a larger turbine is considerably lower as a result.

How much electricity do you use?

You can look at your ESB bill to see how many units of electricity you use. Of course, you won’t use these at exactly the same time that your turbine is producing, so electricity is constantly being bought and sold seamlessly. But in round terms, you can expect the following production from a 2.5kw turbine on your site, depending on the local wind speed. This assumes that you use 40% of the output from the turbine and export the other 60%;

There is some really useful information on this on the ESB site here

PRESS RELEASE 26th Feb 2009
Minister Eamon Ryan today announced a substantial increase in the rate that the ESB is to pay for electricity purchased from householders with their own wind turbine or other renewable energy system. Last week the Commissioner for Energy Regulation had announced that such electricity would be purchased for 9c per KwHr, but the Minister has now effectively increased that rate to 19c for the first 4,000 turbines to be connected over the next three years.

The subsidy of an extra 10c applies only to the first 3,000KwHrs annually. This means that smaller turbines, or turbines on poorer sites will receive more support, while limiting the support for larger turbines. This may be fair enough because the intention of microgeneration is to meet a households own needs primarily, not just to install a large turbine for exporting to the grid.

We believe that the move will provide an enormous boost, not just for our business, but for many others trying to create Green Collar jobs. At a rate of 9c, we had estimated that our 2.5Kw turbine would be viable on very windy exposed sites – the new tariff substantially increases the number of sites on which domestic wind turbines become viable. The estimated payback time for a turbine on a site with an average wind speed of 6 m/sec is reduced from 17 years to 11 years by the change. For most householders, the change means an increase of over 50% in overall revenue from their turbine.

We have the best wind in Europe, and a high percentage us live in one-off houses built on good wind energy sites. Any turbine with a proven track record on our Atlantic coastline will find easy access to other EU markets, and this is exactly the sort of opportunity we should be developing here. Our business development had been hamstrung, because up to recently the ESB would not buy surplus electricity.

We are keen to ensure that turbines are only sold where they will work, and is critical of companies who, in the past, sold rooftop turbines in housing estates where they produced little or no electricity. The price increase will only make turbines viable in sites that have good wind conditions, and those in doubt should carefully assess their site. A turbine needs to be wide open to wind from any direction between south-west and north-west, and any turbulence from buildings or hedges upwind of it will decimate the productivity of any wind turbine.

Here are a few photos for media and other use;

Click on the link to see the photo. Right click on the link and select “save target as” to download it as a file.

Quentin Gargan and Dougie Blair of Turbotricity examine prototype turbines Click Here

Quentin Gargan with Turbotricity tower and blade set in West Cork. Click Here

Turbotricity’s Downwind Turbine Design Click Here

How not to fit a wind turbine – David Cameron’s house with a wind turbine which would mostg likely have been ineffective (had it not been in contravention of planning) Click Here (© Getty Images)

We sent out the following press release last night. INN took it up for their syndicated news service to local radio stations, and I’ve done two other interviews so far, as well as receiving heaps of enquires, so it seems to be welcome news!

ESB to purchase electricity from domestic wind turbines

The Commissioner for Energy Regulation has announced that the ESB is to buy electricity from so-called “micro generators” – householders who have their own wind generators or other renewable electricity systems. The price has been set at 9c per unit.

Turbotricity, an Irish company currently developing household wind turbines has welcomed the move. “Up to now, households with a wind turbine had to use a large bank of forklift batteries to store their power, involving additional costs and maintenance. It makes far more sense to sell surplus power to the grid and buy back extra energy when it is needed” said Quentin Gargan, MD of Turbotricity.

The company has argued that there is an opportunity for Ireland to become a world leader in the production of domestic wind turbines. “We have the best wind in Europe, and a high percentage us live in one-off houses in good wind energy sites” said Gargan. “A turbine which has established a reputation for survival on our Atlantic coastline will find easy access to other EU markets”.

Turbotricity, based in West Cork, is launching a rugged 2.5Kw turbine designed for Atlantic conditions. On most sites, the company expects to install these for between less than €12,000, including a free-standing tower and grid controller. The company’s development has been hamstrung because up to now, ESB would not pay for surplus electricity which was simply spilled onto the grid.

“We strongly argued for a higher feed-in tariff to support this industry”, said Gargan. “When it comes to wind energy, the large turbines are dominated by other countries, against whom Irish industry can never hope to compete. However, domestic wind turbines are made with smaller components, all of which could easily be manufactured here, and it is important that Ireland develops a strong industry in this growing market sector. It is our aim to mass produce turbines and bring prices down so that safe and effective wind turbines can have a sensible payback time, and the current offering from ESB will certainly help”.

The Commissioner for Energy Regulation has decided that the ESB offer is to stand as is. You can find their decision document by clicking here.

Its good news – at least we are getting paid something for the electricity we spill to the grid, though a higher feed in charge would have been a welcome boost. According to the CER document, it would require a shift in government policy for any subvention to encourage renewables. The document states that;

The development of a long term investment policy and any premium/support is a matter for Government policy and is outside the Commission’s remit. Additionally, the information gathered by the PES from the interim export tariff, will provide valuable information in terms of time and scale of export, which is critical if an enduring solution regarding export tariff structures is to be developed.

People selling electricity to the grid will have to accept an annual payment from ESB – however, much of the arrangement is temporary, so there is hope of improvements as more microgeneration gets onto the grid.

Also on the plus side, the Commission said that it might extend the number of free interval meters for people putting in their own microgeneration. At present the first 100 such meters are free of charge.

But all of this is beyond the wildest dreams we would have had when we first started developing our turbine – at that time we expected a zero feed in charge, so this quite a bonus and should give us a busy start when we launch our tubine.

Our Proven instructions insisted that the base of the turbine sit flat on the concrete, and be floated into place. We found that most other tower installers don’t do this – it is tricky getting the base level, and ensuring that you have no air under it, and even at that, the vibration over time can soften the concrete under the tower. I’ve seen two systems (including our own) which have slight movement in the base with water ingress under it.

It is essential that the hole for the foundation has vertical sides - a foundation that slopes in towards the bottom would allow rocking...

So we did what many other commercial tower installers do. You put in threaded bar, with a template top and bottom to ensure that the bars are properaly spaced and lined up. Pour the concrete, and then mount the turbine base a few millimeters above the concrete on the threaded bar. You can use nuts and washers under the base to level it.

Drop in threaded bar with plates top and bottom. Iron is optional if you use fibres in cement mix

The whole procedure should take about 4 hours from digger arriving on-site. We used a mini-digger to dig a hole 1.2m wide and 1.5m deep. It is important that the sides are vertical, not sloping in towards the bottom. A turbine foundation must never be shuttered and back-filled, so getting a hole in the ground with vertical sides is essential. In fact, we had trouble sticking to the 1.2m on the width and ended up with a slighly rectangular hole because the bucket on the digger couldn’t get a hole that deep with vertical sides.

Insert pipe for cable run in centre of frame. Cover pipe end and threaded bar to prevent cement getting in

We then set up shuttering around the top of the hole to allow the plinth rise slightly above ground. Because the ground isn’t level the shuttering was 9″ high at the bottom and 4″ high at the top. We set up the threaded bar with its templates top and bottom, and put ironwork at various heights along this. You don’t need iron if you use fibres in the cement mix.

We also dug a trench 1m deep for the armoured cable running from the house to the turbine. We ran a 2″ alkathene pipe from this trench into the centre of the template and the cable will run inside this pipe after the cement is cured.

We covered the end of the pipe with sileage tape, and covered the thraded bar with fingers off an old rubber glove to prevent cement blocking them up.

After pouring concrete, remove shuttering, clean off the threaded bar and leave the whole thing for two weeks to harden off

We needed 3 cubic metres of 40 newton concrete (because our hole was a wee bit on the wide side – normally about 2.25 cubic metres should have been enough).

We poured the concrete and used a vibratory poker to ensure that all air was removed. Then cleaned up our tools and called it a day.

The following morning, we removed the shuttering and cleaned off the threaded bar with a wirebrush. We now have to wait two weeks before mounting the turbine, but in the meantime, we can run the armoured cable to the fusebox and get the wiring done.