Revised plans

This eventful day ended with a small change of plan, and hopefully a shorter wait before I get the Sun to push electrons around my house. The chap from Installation Company phoned after I had emailed him to let him know of my roof measurements. We reckon we can get 20 Sharp ND-175E1 panels onto the roof, probably arranged as a 9 by 2 array with two extra panels below. To convert DC to AC, we'll use a Diehl Platinum 3100S inverter. It's a big brute but as it will be going into the loft, there will be plenty of room for it. Installation Company find it easier to source these components which hopefully means the system should be installed sooner rather than later.

An interesting sideline is that the inverter has a comprehensive display on its front panel which includes a smart little graph of power production over a day. It also appears to be backlit. I like the idea of pointing a wireless webcam at it so I can see it downstairs, but it leaves me with a problem. I'd also like to see the generation meter. Can I arrange things to have a single camera see both displays? Is having two cameras a silly idea?

Installation Company emailed me a revised quote (same price) late afternoon. I'll get the acceptance form and a deposit off to them real quick. Movement... at last!

Loan at last

It only took twice as long as they said it would, but Energy Saving Scotland (ESS) finally approved my loan. It made for an interesting morning. I phoned ESS first thing and enquired about my application that had thus far taken twice as long as it should have. The lady at the other end informed me that a letter had been sent out yesterday and that approval had been given. Yay!

I then phoned Installation Company and decided to go down to their premises and chat directly. During this visit, various things were learned and a few issues came up. One was the availability of the Topsola panels that we had been quoted for. End of May was their earliest date. An alternative panel they can supply is made by Sharp but they have a different aspect ratio - short and fat instead of long and thin. There was doubt whether they would fit on the roof. A chap is coming out at teatime to check the roof's dimensions. In the meantime, I did a bit of measuring myself.

I reckon the roof pitch is 9.6 by 4.6 metres. If an 8 by 2 array of Sharp panels was set up in portrait orientation, with a further 4 panels arranged in landscape orientation along the bottom, that would give an array of 8 by 3.6 metres - well within the roof's edges and it allows for the 200 mm of roof space that has to be left all around. The question is whether the cabling of this layout would be acceptable. I'll ask the chap when he gets here. Another issue with layout is to leave enough room for a solar thermal array in the future.

Next is the availability of inverters. The Sunny Boy 3300 model I was quoted for is currently difficult to get hold of. They can supply a much larger inverter from another manufacturer. Now originally, I had thought it best to have the inverter and meter under the stairs. However, it was pointed out that it might be better to have it in the loft. The shorter cable run to the meter means fewer power losses before it gets metered for payment of the Feed-in Tariff (FiT). If so, I could maybe accommodate the large inverter.

If the generation meter goes up in the loft, there is the issue of gathering readings from it. For the purposes of metering for the FiTs payments, access to the meter only needs to be gained every few months. However, I'm a technophile who loves his spreadsheets and I'd want a reading every evening. There are various options.

1. Sunny Beam. This expensive kit (over £350) is only available for the Sunny Boy inverters and I may end up not getting one of those.

2. Wireless energy monitor. For between £30 and £45, these will send readings to a desktop unit based on their own measurements of power flow from the inverter. Their chief disadvantage in my head is they are likely to give a different reading from the meter that will be used for the payment of the Feed-in Tariff (FiT). I'd prefer to know the readings that reflect the money.

3. Wireless webcam. This is a daft, but wonderfully workable idea that came to me. Wireless webcams like this one link into the house WiFi system. They have their own webserver software built in. If one could be set up peering permanently at the FiT meter, I can gather a reading from it when I like. Appropriate LED lighting would have to be set up, as would a mains power feed.

By the time we got home, the postie had delivered the ESS letter about the loan. Happy days.

Wireless energy monitor

Had a chat with Installation Company about when inverters will become available and the latter half of May looks likely. Apparently, component supply problems with the manufacturer are at the root of the issue. They did suggest I get back onto the people at Energy Saving Scotland to chase up the progress of my loan.

They also pointed out that at over £300, the Sunny Beam monitoring system I was looking at is a very expensive way to go about keeping an eye on the output of the panels. Instead, they suggested I search for 'wireless energy monitor'. I did. For somewhere between £30 and £45, I could get a system that will do a decent job for me. Two systems come to light in the search. The Owl is very common. Tesco sell them. Another is by Efergy. Some of these will even connect to a computer and display their results as graphs though apparently their data structure is rather proprietary. You can't load the files into, say, Excel.

These units are meant to monitor energy usage in the home. They easy to use and install. They include a sensor that is simply clipped around the live cable to your electricity meter. This sensor is connected to a transmitter unit that sends the measurements to a receiver which displays the results. The suggestion from Installation Company is to use one of these to monitor the AC electrical output from the inverter.

On the Amazon UK page for the Owl unit, some reviewers have pointed out that the system lacks sensitivity. It will give you a reasonable idea of the bulk power flowing though the cable but it struggles to accurately respond to the change caused by, say, a 60-watt bulb being switched on. However, it looks like a fun gadget that I had not seen before and I might get one just to play with.

One thing to point out is that I don't actually need any of these toys to monitor the daily operation of the panels. The inverter will have a display, and there will be an approved meter on its output for the purpose of working out the Feed-in Tariff I am to be paid. I can gather these numbers each evening for the spreadsheet as I do now.

Long delays-2

Our extraordinary spring continues with long, sunny April days burning away raw memories of a cold, harsh winter. With each day, I ponder at the wasted photons striking my roof and the pennies that could have been gathered from them. Now I will have to wait a while longer.

When I received my quote from Installation Company, they specified a SMA SB3000 inverter, and like many would, I immediately hit the web to find out more. It turned out that the number in that designation, 3000, referred to its power rating and this one was rated at 3 kW. This seemed strange because the array of panels I was ordering are to have a peak capacity of 3.5 kW. I wondered whether this underspecification was intended as a way of keeping costs down. 

Solar photovoltaic systems generate direct current (DC). Like a battery, they have a positive and a negative terminal and the electricity from them flows in only one direction. However, the power systems within our homes and factories work using alternating current (AC). Here the electricity flows first in one direction and then in the other, swapping polarities and back again fifty times a second. It is the job of the inverter to convert the DC power from the panels into AC that can work with the domestic supply, and it will do so in sympathy with it - making sure that positive and negative are the right way round at the right time. As it does so, it has to be able to handle the amount of power being generated by the panels.

For most of the time, a 3 kW inverter would be absolutely fine. Given cloud, seasonal sun or times of the day when the illumination is not optimum, there is almost no time in the year when my system will generate power at its peak capacity. That can only occur when the Sun is shining through a clear sky at an exactly perpendicular angle to clean panels. My first guess was that Installation Company had figured there was no need to supply an inverter rated to match the array for this very reason. I brought it up with my contact within the firm and he took the opposite view. The 3 kW inverter was wrong and it should be a more muscular version, the SB3300. In fact, there may be a time of year, in the early afternoon on a sunny June day, that the illumination on the panels might just stretch the ability of a 3 kW inverter to do the job.

Today, I decided to see if Installation Company had a firm date for my panels to be installed. The lady's answer was that their supplier was having difficulty sourcing the correct inverter and the signals were that the units wouldn't arrive until the latter half of May. That seems to put the installation back about 4 weeks from when I had hoped. The good news is that I can afford to wait longer for the bureaucracy behind my loan application to do its stuff. The bad news is mild frustration and the thought of a zillion more springtime photons landing uselessly on my roof.

One interesting sidenote is that while the SB3000 is rated for a peak of 3 kW, the SB3300 will handle a peak of 3.6 kW, more than enough for my system. Another fascinating nugget for this gadgetboy is that the inverter can have a Bluetooth interface which allows it to be monitored remotely, and to a very high extent; heaven for someone like myself who loves monitoring systems. A little remote display called the Sunny Beam will keep daily reports of the power from the panels and will pass that information into my computer via USB. Oh, heaven! It will even draw little histogram graphs to show how the generation of power was distributed over a day. I'll investigate this more later.

Loan delays

I finally got through to the Energy Saving Trust in Edinburgh. The lady I spoke to said there were quite a few applications in before mine so news about my loan for installing solar panels is not imminent. I did mention to her that I was in a queue with Installation Company with 2 to 3 weeks remaining. Her suggestion was that I hold off postponing the job until a week or so before it happens and if I haven't heard anything by then, give them a phone.

In truth, I don't have a definite date for the installation. My only clue came from a conversation with an employee of Installation Company who I spoke to on Easter Sunday and who said about 4 weeks. That put it at the beginning of May.

Two steps forward, one back

We're having a fabulously sunny mid-April and it frustrates me a little thinking about all those photons landing on my roof, their energy only to be absorbed and dissipated by the tiles. I am having to wait; wait for the Energy Saving Trust to decide whether they are going to give me a loan, and wait for the date to arrive when Installation Company will come and install my solar panels. I think that will be about two to three weeks away.

The problem is that if I want to take advantage of the loan, the installation work cannot begin until the loan has been agreed. EST are supposed to have made a decision within 15 working days and that has time has long passed, so I decided I ought to chase them up. It did not work out well. I started with their freefone number and a lady gave me another number in Edinburgh to phone. Every time I phone that, I get an automated message telling me that they are not available. I'll console myself with the idea that if the installation date arrives and they still haven't agreed the loan, I'll go ahead on my own finances.

Meanwhile I took a couple of steps forward. First, I changed my energy supplier from Scottish Power to EDF Energy. Depending on whether you believe EDF's figures or mine, I'll save between 26% and 30% on my gas and electricity bill in the long term. Interestingly, my estimate is the more optimistic of the two. The tariff I'm on only lasts until June 2011, but even then, their standard tariff is cheaper than what I'm paying Scottish Power.

Of course, this really has little to do with solar power and anyone can change to a cheaper supplier. However, EDF Energy are a registered supplier for the payment of Feed-in Tariffs. This means that when the solar panels are installed, EDF will look after the payments due to me for units generated. Here's how it is supposed to work. Installation Company, who are MCS registered (and they must be for the FiTs scheme) will register my installation on a national database. They will also give me a certificate. I'll apply to EDF for FiT payment. They'll cross-check me on the database and arrange how often payments will get sent to me.

My second little step was to send a letter to the local planning authority along with a simple plan, requesting a letter from them that confirms I don't need to apply for planning permission for this.

Right, I'll go and sit out in the sunshine and ponder my lost photons.

Loan bureaucracy

The Energy Saving Trust sent me a letter on 1 April to let me know of the changes to the grants and loans schemes that have taken place with the introduction of the FiTs. Whereas their letter of 22 March merely informed me of the reduction in the loan amount, at least this one informed me of the fact that the grant for which I had applied was being discontinued - as well as restating the position on loans. The letter doesn't actually say that I'm not getting the grant. Rather, it states that I will hear from them shortly. However, I'll assume I won't get a penny. I wish they'd just get on with it.

Meanwhile, I've heard that my panel installation ought to occur in about 4 weeks. The funding is in place and I'm ready to go ahead, loan or no loan. With relatives over to visit for Easter Sunday, I found myself telling one of them about the financial implications of microgeneration. I think he was intrigued.

Media coverage of FiTs

My ears pricked up while sipping my morning tea when the Today programme gave a mention of Feed-in Tariffs (FiTs) on the day that they are introduced. Later in the day, I managed to catch coverage on The World at One and on Reporting Scotland.

It was interesting to see the range of spin given to the story. The earlier bulletins focussed on the fact that the payments to microgenerators (like me soon, hopefully) would come out of the pockets of all the other power consumers. A figure of £11 per year was quoted as being the amount non-generating households would have to stump up for this scheme.

The regional news programme took a completely different, and much more positive slant. It looked at a little village where residents intended to erect wind turbines for the benefit of the village. I'll come back to this in a moment. All of the coverage failed to project what I believe is the most important aspect of this move. Feed-in tariffs are going to revolutionise our attitudes towards solar power. PV panels will become the must-have accessory to have on your home. I'll predict a very bright future for businesses that install them.

For those who wonder how a Feed-in Tariff works, here's my quick explanation.

Just now, electricity costs about 12 pence per unit (or kilowatt-hour, kWh). If you generate your own electricity, you will get an amount of money for every unit you make. For a 20-panel system that I have in mind, this is 41.3 pence. This tariff is guaranteed for 25 years and is linked to the RPI. There is a small additional tariff if you export your power onto the grid rather then use it yourself. The upshot for a homeowner like me is that for an outlay of less than £15,000, I will earn enough to pay off the panels and have essentially free electricity.

Back to the wind turbines. If ever there was a part of the world that was rich in untapped wind energy, it has to be the Outer Hebrides off Scotland's northwest coast. A few years ago, a company came in and laid out plans to cover Barvas Moor with hundreds of giant turbines. The people of Lewis were not happy on the whole and a large campaign was successful in stopping the development. 

A few hundred miles away, another company presented plans to the village of Fintry in Stirlingshire for 12 turbines on the nearby hills. A few thousands of pounds were offered to the village as a device to smooth the acceptance. With great wisdom, the village rejected the offer. With their next move, they played a blinder. They convinced the company to erect a thirteenth turbine, the proceeds of which would pay for its cost and the remainder would go to the village.

According to this Scotsman article, the villagers will get £100,000 a year for ten years while the cost of the turbine is paid off, then an additional £4 million in the succeeding 15 years. Already, this has allowed the villagers to carry out a programme to insulate all the homes in Fintry, thereby reducing the heating bills of everyone. With that completed, they have begun to replace old, inefficient boilers throughout the village. They have many plans to further improve the energy efficiency of the village and upgrade its facilities. 

I hugely applaud this way of bringing generation to the community. How sad then that the communities of Lewis could not use Fintry's example and take control of the plentiful wind energy available to them.