When we lived in the city, getting ready for winter meant closing the windows. Here on the farm, there’s a bit more to it.
First the garden. After protecting the tender crops like tomatoes and peppers against the frost until the last possible fruit was picked, we dug the last of the potatoes and picked the winter squash. Both go into the cold room for keeping until February or so. A foot-thick mulch of straw on the carrots keeps the ground from freezing so we can dig them all winter. The leeks could be held over the same way, but they never last long enough. Leeks covered in sliced black olives and baked in the oven in olive oil are one of my favourite treats.
Then the animals. After reviewing our annual meat orders, we take cattle, pigs, lambs, or chickens (whatever we are raising that year) to the butcher, then arrange for custom cuts. Will that be more steaks or roasts; more stew meat, more ground, or sausage?
We always feel relieved that we get through another year without major losses (except for the time a bear took a lamb from within a hundred feet of the house). We also feel a bit empty as we look around and ponder the absence of animals that we’ve come to know a bit. We bring feeders in out of the weather and make sure feeders, hay, and water are ready for overwintering sheep and cattle.
The woodstove pipes and chimney are checked at Thanksgiving and Easter. We cover the roses with straw, bring in wind chimes and the pots of parsley, open the outside vents to the insulated box surrounding our refrigerator in the kitchen so the cool outside air eases its load a bit, and fill the pick-up with wood for the basement woodroom.
In a solar-powered house, we always check the system over, too. There is little maintenance on the solar modules other than brushing snow away now and then, and our generator is in its own snug, heated building. The third part of the system is the battery bank. We used to have over 100 NiCad batteries in 14 cabinets around the perimeter of the basement shop to store the power we make.
Three years ago we traded them all in for six lead-acid batteries that do a better job. Each of these batteries has a footprint of 16 cm by 23 cm and is 70 cm high, so six of these tall, skinny cells easily fit in a tidy cabinet 50 cm by 140 cm, with a hinged top that doubles as extra work space.
Because batteries charge and discharge at slightly different rates, every two months or so we equalize them, or give them a sustained overcharge to even them out again. Imagine six large jugs of water. If you pour water out of each and fill it again, over time the water levels in the jugs will vary. It’s the same with batteries. Equalizing is like filling each jug of water so it overflows a bit, making them all the same.
The batteries become slightly warm when equalized and also bubble hydrogen gas, so it’s not a great idea to peer into them with a lighted match. Even under normal charging, the batteries will bubble a bit on a sunny day, and this water has to be replaced every month or so.
When we first installed these new lead-acid batteries, we also installed hydro-caps, a small plastic bulb that fits on the top and is supposed to take the gaseous hydrogen and turn it back into water so you don’t have to top up the water so frequently. Good idea except that one of our hydro-caps plugged up earlier this year. I opened the cabinet to check on the cells and the cap was lying off to the side after it had shot off the top of the battery. Unfortunately, the force of the hydrogen also cracked the battery casing and we lost some of the electrolyte.
This loss of electrolyte exposed the plate to the air and it sulfated or corroded so it wouldn’t hold a charge properly. We worked all summer with extra charging on sunny days trying to bring it back but, alas, it couldn’t be done while the cell was still hooked into our system so we had to replace it.
The lucky part was that the cell was the one on the end of the cabinet and easy to get to. The unlucky part was that it weighed over 120 kg full of electrolyte. The first step was to discharge all six cells in the battery bank so there was no chance they would be giving off hydrogen to be ignited by our torch. That’s a pretty exciting way to put a battery into orbit, but the flight path would be through the roof of our house so we really didn’t want that to happen.
Next we dismantled the end of the cabinet. Then we drilled and cut the connections. Now, these batteries aren’t just hooked together with cables. They are joined by lead bridges that are melted or “burned” on. A mold is placed over the terminals, then that mold is filled with molten lead to form a solid connection.
We drilled the centre of the old connections with a 2-cm drill that made shiny spirals of lead about 15 cm long that would be lovely on a Christmas tree. Then we popped off the old bridges, slid out the old battery onto a hand truck, then slid in the new one and re-bridged the connections, filling them with molten lead again.
Then we added a cube of sulfuric acid and watched the plates bubble as they slowly absorbed the acid. An hour later they had nearly stopped, so we could turn on the generator and recharge all six cells to their normal capacity. This took the generator about eight hours on the first day, then four hours a day for a week to completely charge the new battery bank.
Now we have a woodroom filled with stored heat and batteries filled with stored power. It’s all part of getting ready for winter when living in a solar-powered house.