Beginning

When I was about 17 years old (which was in 1992) I received a copy of the catalogue of the German electronics mail-order company Conrad Electronic, which was only become active in the Netherlands. They sell everything from resistors and electronic kits to radio transmitters and modelling suplies. I could browse the book for days at a time and dream about what I would buy and build. One of the things they sold were solar panels in all sorts and sizes, from small 10x10cm thin-film panels to large (large at the time) 100Wp panels and much more. The large panels were prohibitively expensive – 1000 Duitch guilders and more -  and that was way out of my league.  I managed to buy a few small panels to charge rechargable batteries and run a radio. Those small-scale experiments fanned my interest in solar panels as I was utterly fascinated by those square pecies of glass generating electricity silently and cleanly when put in the sun. I just didn’t have the money at the time to buy large solar panels, so I would have to be patient for a while.

The first ‘real’ solar panel

A few years later found me living on my own, in a rented apartment. Unfortunately there was no still no space (but in my budget and on my roof) to install a larger solar electric installation, but the thought never left my mind. Unfortunately there was still no space – again both on the roof and in my budget – to buy and install a proper large installation, but the tickle wouldn’t go away. The budget slowly increased so I bought a small 20Wp panel, a 12V lead-acid battery, a charge controller and a 12V compact fluorescent bulb. During the summer months the panel generated enough energy to run the CF bulb, operate my laptop and charge the batteries of mobile devices like cell phones etc. During the winter months hardly any energy was produced because my roof terrace was shaded by trees. This system worked for few years without any problems, and taught me a lot about solar electric systems. In that same period the internet was rapidly becoming a mature source of information and many websites about solar energy, sustainability and everything around that began appearing. That aroused my interest to find out more about things like energy and the environment. Partly because of this I began to look critically at my energy consumption, and I began increasing the energy efficiency of my household. After purchasing a power meter I discovered that my second-hand fridge consumed nearly 900kWh per year (which is now just about the yearly consumption of our two-personhousehold). I installed compactfluorescent bulbs nearly everywhere, bought energy efficient appliances and installed power strips with a switch so I could eliminate all standby power. Because I did not have my own electricity meter (energy was included in the rent) I could not measure how much energy and money I was saving, but it must have been a lot.

The first grid-connected installation

Another couple of years later my girlfriend and I rented a top-level apartment. I installed the 20Wp solar panel on the roof where it kept working perfectly. After a while the urge to finally start ‘for real’ became stronger and stronger. I prepared by reading everything I could find and grid-connected solar installations, and also exchanged many e-mails with people who knew a lot about it (a.o. Floris Wouterlood en Peter Segaar) so that I knew exactly what I was getting into. I also had to save quite a lot of money because solar panels don’t come cheap and I certainly didn’t want to borrow money for them. The rental organisation gave permission to install the panels and in June of 2006 I took the plunge and ordered a 555Wp DIY-installation at SolarNRG. Installing it on the roof was a lot of work, because all parts including 225kg of ballast (tiles) had to be carried up four stairs and a ladder. It took an entire evening of sweating but at the end of that evening the first Watts were flwoing into the grid. I started this website in that same period, at first under the complicated address of our internet service provider, but later under the easier to remember address www.solarwebsite.nl. The rental organisation was so impressed with what we did that they sent over a reporter and a photographer from their bimonthly publication to write about the solar panels  so other tenants could see what was possible, even in a rental home.

Extension I

I was very happy and satisfied with the installation as it was now sitting on the roof, but after a while the familiar urge stared to make itself felt again. The 555Wp installation produced about half our electrical consumption and wanted to add more solar panels to produce a larger part of our consumption. The space on the roof was limited, a.o. by a small flue pipe giving considerable shadow, and of course he budget was not unlimited either. That’s why I bought a 300Wp secondhand installation in the beginning of 2007, bringing the total installation size up to 855Wp. At that point it was producing about 80% of our electricity consumption.

Moving + extension II

At he end of 2007 we bought our current home which we moved into by the beginning of 2008. We took the solar panels with us of course, but they spent a few months in the shed until we had finished redecorating the house. I also spent that period thinking about the choice between installing them myself or having it done for me. In in the end I chose to have it done (again by SolarNRG) because our house has a sloped roof and I’m a bit afraid of heights. At the same time I had the the installation extended by a final 510 because our roof is not pointing south (it’s pointing west-south-west) and this decreased the yearly production somewhat. I also expected a higher electrical consumption because the house came with a large electric oven, some halogen lighting here and there and it’s simply a larger house. There was now a total of 1365Wp on the roof.

Solar-awning: extension III

Although the installation now covered our entire electricity consumption (it even exceeded it) we still had a problem of an entirely different kind: we hated the awning above the front door. Coincidence would have me browsing Markplaats (a Dutch classified advertising website) and I bumped into a friendly-priced 100Wp solar panel including a grid-connected inverter. The panel was nearly the same size as the existing awning. After constructing a few aluminium struts mounting the panel above the front door was easy. Although the OK4 inverter is designed to be mounted outside, on the back of the solar panel, I have mounted it indoors to prolong its lifespan. I don’t expect a very high production from this panel, probably around 50kWh per year, but that’s okay. It looks nice, the sparkling blue of the solar cells is a striking sight and any electricity it produces is more than any other awning in the street. This panel brings the total size of our installation to 1465Wp.

Extension IV

Two of this website’s sponsors, Beldezon () en Harrems Zonnepanelen (), kindly donated a 660Wp installation to me at the beginning of 2010. Although we had already installed enough solar panels to create an electricity surplus I could not just leave those panels go to waste in the shed. I installed these panels on top of the flat roof of the extension on the east-north-east side of our house, which is obviously not very optimal. I estimate that this orientation will reduce the performance by about 35% when compared to a south-facing installation. That’s not bad but it doesn’t really matter as the installation was nearly free anyway.

Extension V

The 120Wp panel on our shed

On January 21st, 2012 our installation was extended again with a small 120Wp solar panel. The panel was a gift and it had been stored in the shed for two years. Unfortunately our shed was in a bad state (it didn’t even have electricity) and only after I’d renovated it last summer did it become possible to install the panel on the shed’s roof. Because the panel is designed to charge 12V batteries the nominal voltage is low, around 17V. This means that common small grid-tie inverters, which can be found second-hand here an there, are not usable because they require a higher voltage. I found the solution in the form of a SUN-250G inverter, made in China and available in both a low- and high-voltage version. The inverter is heavily oversized (a 120Wp solar panel on a 250W inverter) and that will impact the efficiency negatively, but that can’t be helped. At the time of writing (half March 2012) the installation functions perfectly. This extension brings the total installed capacity to 2245Wp. There’s hardly any more room for extra solar panels now, so it would seem that I’m done extending the installation. Then again, that’s what I thought after the last extension

Current status

Our installation presented schematically

This diagram shows schematically how our solar system looks at this moment (March 2012). The panels are not drawn to scale, for instance the 100 Wp panel above our front door is much smaller than all the other panels. Also visible in the diagram are the six Plugwise measuring plugs which I use to monitor the performance of all sub-installations. Our installation is relatively complex, because we bought all sub-installations at different times. Because of this we have a hodgepodge of panels and inverters. Most people who buy a large installation in one go will choose one large inverter. Despite the complexity I’m happy we did it this way, because it allowed us to spread the costs over time. It also shows the flexibility of solar power: you can expand a system at any time.

Future

I think that things in the solar electricity are about finished now: the installation produces more than we use so installing any more panels would not make sense. Our consumption could still grow a bit without leading to a postive electricity bill. Future developments will mostly be in the area of heating and drinking water. These are a few wishes I still have:

• Solar hot water system
• Hotfill system for the washing machine and/or dishwasher
• Heat recovery system on the shower
• A rainwater system for flushing one or both of our toilets

It’s likely that not all these wishes will come true, for instance I’s not certain a solar hot water system can be implemented on our rather small attic without precluding its use as living space. If a solar hot water system proves to be impossible or impractical the hotfill system would also be much less useful as I would be better off using our own solar electricity to heat water than natural gas. So there is still a lot of deliberation to do, but that keeps it fun and interesting!