The Digital Agency for International Development

Solar Diaries - Day 5 & 6 - Behaviour Modification and Diet Failure

By Alan Jackson on 18 September 2010

Day 5

A cloudy day. This is one of the interesting things about taking responsibility for my electricity production - it's not just that I replace the electricity I used to use. The awareness I am getting is modifying my behaviour.

I generally think of myself as someone who tries not to waste energy. I turn lights off when I leave rooms etc. But trying to run my working life off an under-dimensioned solar power system is being a real education in energy wastage.

Today I'm having the usual one hour lunch break. Normally I would probably leave my computer on. Today I don't even suspend the laptop, I shut it down completely... and unplug its 12 volt regulator. I want to see 0.00 amps flowing out of the battery when I'm not using it.

I'm also aware that I'm starting the day with a fairly empty battery and it's cloudy - so today I'm not using the external monitor...

(time passes)

...I got through the day but around 5pm the solar charger shut down the load to protect the battery from getting too flat. So I worked the rest of the day, up to 6:30, using the internal battery of the laptop. By the end of the day I've got 10 minutes battery left on my laptop, about the same on the Samsung / PixelQi netbook and a shut down deep cycle battery. Hmmm. (I'm actually writing this blog entry on Day 6 because I ran out of power on Day 5)

Day 6

The forecast was for sun this morning, potentially worsening through the day. I'm starting the day with an empty solar battery and no reserves on the laptops. I have to get up early (early for me anyway, if not early by international standards) to get the panel out. At a push, the sun starts being usable from about 8am so I've got 2 hours to get enough charge on the battery. PV Panel out the front of the house

Luckily, yesterday evening, the 15m extension cables for the PV panel arrived so I don't have to lug the battery around. I start by dragging the panel upstairs to the east facing bedroom to try and get the early sun. By the time I've got it all plugged in the sun's rising high enough that it's hitting the doorstep out the front. I take it down there instead. The panel's bigger than any of the panes in our windows so there would always be a shadow from the window frame which would seriously reduce the power output.

As the minutes tick by I'm glued to the multi-meter watching the voltage slowly climb, repeatedly running out the front, rotating the panel to face the sun. (There is some debate about whether it is better to spend money on mechanical trackers or on more static PV panels instead. However manual tracking is free... if a complete pain in the back-side.) It gets to 10am, time to start work, and the solar charger is still disconnecting the load. I use my last few minutes of laptop battery to skype in to the office for the morning meeting and then, with a sad face, I plug the laptop into the mains. I've broken my mains-free diet. And what's even more irritating is it's a gloriously sunny day. There's probably enough power coming off the PV panel to run the laptop directly, but I'm not set up to do that... yet. Digital-Resilience #fail.

I'm hoping the battery will get enough charge over the weekend to see me through next week. Until I've built my office-cum-shed with the south-facing roof in the garden, I've got nothing to attach the PV panel to in a permanent way. We're away for the weekend and I'm worried the panel might go for a walk if I leave it out in the garden so it's currently inside standing vertical against a west-facing window. Knowing the PV panel is less than optimally placed is taking some of the joy out of the fabulous sunshine we're having today. I did try and persuade the family to bring the battery and panel away with us. They think I'm obsessed. Luckily for family relations the panel is too big to fit in the boot of the car and the battery is too heavy to carry on the train.

If I make even more gridbeam I could, in true agile fashion, just make the roof of the shed.