Good end of month

Having passed the monthly total for January on the 21st with ten days to go, it was looking like being a fairly productive month. This was helped by a period of 4 clear days that really got the panels going, followed up by various mixed days that still produced a handful of units each day. Plus a few surprises - a few instances where cloud was forecasted but better weather materialized. It all helps.
 

Since then, it's been fits and starts. Firstly the highest ever spot reading on the Owl unit (see below) on Jan 26th. Not bad for a 3.43 kW system. I suspect part of this is due to the uneven nature of the weather - I don't get these higher values when the sun is constant. I wonder what the system will be capable of come high summer, given that the inverter is rated above the panels, at least I know whatever they kick out will get used, maybe I can get closer to 4 kW?

Secondly, Jan 27th was another perfect day - wall to wall sun and over 13 kWh generated. We still had the dip at 3:15 pm when the sun descends passed a tree on the horizon, but other than that it was a perfect trace with over 2500W being kicked out in the middle of the day. Not bad for January, it just goes to show how the slightly longer days & higher sun angle increase the output, and that's just comparing to a few weeks back. Roll on some proper spring days!

Jan so far

January has been a little mixed so far - some poor days and a couple of better ones. Plus a couple of moderately good days (well beyond the forecasted conditions). It's always nice to get a handful of units produced that weren't expected.

However, it now looks like we're heading into a period of high pressure - clear skies, frosts and plenty of winter sun for the panels to lock into. Today (13/1/12) looks like being a 10 kWh day, but it's hard to tell exactly, but either way we wont be far out. If this weather holds for next few days than an average 7-8 units for 5 days will do wonders for the performance against target. Whilst I don't expect to beat the performance target by much, it's always nice to sit back and enjoy all that free power.

It's nice to see the evenings starting to get lighter, its only a few minutes a day, but given that this starts to overlap with my evening commute home, it's most welcome. The mornings wont start to change for my morning commute for quite some time (maybe March), but it's nice to see some signs that the seasons are starting to change.

On a separate note, I managed to get up the loft recently and get a rough measure of the pitch of the roof. According to my rough calculations, the roof's pitch is a little over 45 degrees, maybe closer to 47 degrees. For some reason I'd always assumed it was closer to 50, but now I know. I've subsequently reworked the power factor values for the table at the top of this blog to reflect this. In theory this will make a slight change to the performance of the system, but is likely to be slight.

Watts at last

So today was the first day of generating real electricity. 

About 8am the OWL meter started to show about 120W - more than the background reading of 85W that seems to persist throughout (presumably the load of the inverter and panels). By 9am things had started to lift up to 500W or so and by 10am we'd seen upwards of 700W on several occasions.

The weather was not ideal - grey cloud clearing later, but from time to time the sun threatened to break through and we topped 1000W a few times. Around lunchtime we hit a mighty 1.2kW briefly before settling into a steady 700-900W for a good hour or so. 

The sky cleared later on, but the power started to wane as the angle and height of the sun changed. And at about 4pm the light was gone. 

Despite the mixed weather, and shadows on the panels from the scaffolding (due to go next week), we managed to produce 3.3kWh today - not bad for mid November, and a start.

Whilst this is hardly going to compete against the national grid, it's made a hole in today's bill, although not enough to export any juice, it all helps.

Ideally, I wouldn't have installed the system at this time of year, but needs must with the tariff deadline approaching. So anything that gets produced between now and spring is a bonus. 

The next week or so will be interesting to track, as well as trying to understand the impact of the system drain at idle.