Friday, 6 January 2017

09:52 – The cold weather is moving in. We’re expecting 4 to 6 inches (10 to 15 cm) of snow over the next couple of days, with the low temperature Sunday evening to be 8F (-13C). And, as nearly always, a stiff breeze and gusty winds.

In accidental prepping this week, I doubled our PV solar capacity. Back in early November, I ordered a Renogy 400 Watt 12 Volt Monocrystalline Solar Starter Kit with Wanderer. When we were de-cluttering the garage Tuesday, we finally opened that package, which was a box about 2×4 feet plus and a foot or so thick, weighing close to 90 pounds. Inside that outer box, we found two slip-fit thinner boxes, apparently identical, each of which obviously held two of the four solar panels. We opened one, and indeed found two solar panels and nothing else. I assumed, foolishly as it turned out, that the second internal box was identical to the first and that therefore we were missing the other components (charge controller, cables, connectors, etc.) that were supposed to come with the starter kit.

So Wednesday I called Amazon Business tech support and spoke to a very helpful woman named Diana. Based on shipping weights, she agreed with me that there must have been a second box, and couldn’t figure out what had happened to it. So she shipped me a replacement solar starter kit and said just to have UPS pick up the initial partial shipment. Amazon shipped it that day. Then yesterday as we continued cleaning up and organizing the garage, we opened the second internal box from the initial shipment, which (like the first box) looked large enough to contain only the two solar panels. But in fact it also included the rest of the components. placed against the back of one of the solar panels.

I talked to Barbara about it, and said that I’d intended to order a second kit this year, so why not just keep the second kit. She agreed, and I emailed Diana to confess my mistake and tell her just to charge our credit card for the replacement shipment as though it were a new order. That order is to arrive today, so we’ll now have 800W worth of PV solar panels, two Renogy Wanderer PWM charge controllers, and associated cabling and connectors.

The Wanderer charge controller supports four panels feeding a 12VDC battery bank, or eight feeding a 24VDC battery bank. I haven’t decided yet whether to configure it as a dual 12V system or a single 24V system. There are advantages either way, and of course I could if necessary reconfigure it on-the-fly.

But what really matters is that 400W of PV panels was marginal for our emergency needs, while 800W should more than suffice. Renogy claims that “ideal output” of the four-panel setup is 2,000 Wh/day, which obviously assumes five hours/day of full sunlight with a non-tracking mount. Taking into account cloudy days, losses in cabling and the inverter, and so on, it’s much safer to assume actual output at 1,200 Wh/day. With eight panels, that gives us 2.4 kWh/day, which will suffice to let us use our well pump normally, provide minimal LED lighting, communications, etc.