Our little house has been tested this winter. Not by snow (we haven't had much of that), but by single-digit temps. It's been the coldest weather since we moved in a couple years ago, and it's supplied us with more than a few lessons learned:

Floor insulation. The cold that seeps into the house comes up from the floor. We thought the few inches of rigid insulation we put between the floor joists was enough, but we probably should have doubled it. It would have been worth the additional $$. We're thinking we might add insulation underneath the trailer.

Skirting the trailer. We would also benefit from skirting around the trailer, to cut down on the wind running under the house and chilling our floors.

Water pipe insulation. A year ago we happily reported that we'd completed enough upgrades to our system to have flowing water all year, which is something you learn to be happy about when you don't have any running water your first winter. We were wrong. Though they didn't burst (yay!), our pipes froze in a couple places, temporarily cutting off our water supply. The hose from our friend's house to our water tanks should have been deeper in the ground, to get below the freeze line. (If it ever bursts, that's just what we'll do when we replace the hose.) The pipe that runs through the floor joist under our insulation needs heat tape and more insulation, so it won't freeze. 

Cut-off valve. Adding a water cut-off inside the house means we can drain the pipe under the floor when we go into a deep freeze. Hopefully, this will keep the pipe from freezing until we get the chance to add heat tape and insulate it better.

Electric loads. We came home to a 36-degree house when the breaker popped while we were away. We had someone visiting and hadn't warned our guest about issues we've been having with the space heater, water heater and pump drawing power on the same line. If they all go on at the same time, they flip the breaker. We need to take a long look at what we have on each line, what we have on solar (we could move the refrigerator to solar, as it turns out) and how to better manage our electrical draw. (This is Bill's domain; if you have questions, let me know and I'll ask him!)

Wood. We're trying to get better about staying ahead on the log supply for the wood stove. When you need it, you need it—and a cold, winter night is not the time to be out in the dark splitting and sawing. We have one, big metal trashcan full of right-sized logs up in the garage now, and four small cans that sit outside the door on the deck, so we can grab more wood without going anywhere.
 
Backup bucket. We finally remembered to buy a spare 5-gallon plastic bucket, so that we don't have to walk up to the compost barrels in the middle of a snow storm or single-digit temps when the bucket in the toilet gets full. We can just snap a lid on the full bucket and leave it outside the door until a convenient time to bring it up the hill to the barrels.

Air exchanger. The past two winters, we've had to open windows (despite the prevailing temps) if the carbon monoxide alarm goes off, signalling the need for fresh air in the house. Now, with our  exchanger, air is efficiently coming in and going out all the time—with the windows sealed tight.

We've been puzzling over power for our tiny house ever since we made the decision to build a house. We want to reduce our carbon footprint, so renewable energy seems a clear choice. But wind, solar and the like are sizable investments, and our budget is less "sizable." Lots of tiny housers go partially solar for lights and outlets, then augment with energy-efficient propane for cooking, heating and hot water units. But that re-raises the eco dilemma: we don't want to buy new technology (stoves, hot water heaters, etc) that rely on a non-renewable, fracking-associated fuel like propane. 

A solution that balances resources (both financially and ecologically) came to Bill as he was stringing wire through the framing of the house. Why not buy as much solar as we can afford now and take advantage of the generous offer of our landlord to tie into her grid electric for additional power. Hopefully, down the road, we'll move off the grid and go 100% renewable. 

Then we moved on to agonizing over what solar panels, batteries, charge controller and inverter to buy and where to buy them. We don't want the panels on our roof; the house isn't in an ideal spot for sun, and we want a system we can easily expand in the future. A ground-mounted system works for us. We researched and read about battery life and storage capabilities, about sun requirements, about pure sine wave inversion and...the learning curve was steep. So when we heard about an integrated, portable system that comes ready to plug in and power up, it seemed the right fit. It's more expensive than cobbling together our solar setup ourselves, but it meets all our needs for a reasonable markup.

And the winner is: the Solman Classic by SolSolutions. The all-in-one unit comes on wheels, so we will be able to orient it for maximum sun as often as we want. (Evidently, adjusting position to track the sun a couple times a day can bump up power production by as much as 30%.) We can also situate the unit in a field some distance from our shady tiny house site. The 3000 "usable" watts of battery storage (batteries store more watts than can be drawn from them effectively) should have no trouble handling our all-LED lights, outlets (largely for charging devices) and ceiling fans. 

For things that draw a lot of power, we have a hybrid approach. Cooking will be on our alcohol-burning stove/oven by Origo. We'll heat the house with our super-efficient wood-burning stove, the Kimberly by Unforgettable Fire. Our hot water heater and water pump (both still TBD!), Energy Star refrigerator and, should we decide we can't live without one, our microwave all get tied to the grid. The local electric cooperative has a less-than-stellar portfolio of energy: lots of coal power,  no renewable. But it's available on site we can always "un-tie" ourselves down the road. In the short term, we can move more over to solar if we see we're producing enough power.

To make this magic happen, Bill installed two breaker boxes. One will be powered by our battery bank, which in turn will be powered by our three solar panels. The second breaker box draws from the local electric grid. Once the two grounding rods get stuck in the ground and connected to the ground wires, we'll be all powered up. Now, if we only had walls and flooring and...

It's been months since we walked through the shell of our house and decided where we wanted outlets and lights, ceiling fans and refrigerator. But we put off getting started on the wiring because we didn't know where the power was going to come from. 

We would love to be able to say we were going 100% solar— but that's not in the budget. A solar panel/battery system large enough to power our entire house would run well over $10,000. Some tiny housers opt for propane for things like cooking, heating and cooling. But we'd like to stay away from fossils fuels and all things fracking-related. We have the less-expensive option of being grid-tied to our friend's house, but one of our goals for the house is to move toward sustainability, so tying into a power system that derives much of its power from coal plants doesn't seem quite ideal, either.

Our stalemate has finally been broken. We've decided to buy what solar we can afford now: a modest system capable of powering all our outlets (largely for charging devices), LED lighting and ceiling fans. For now, we'll tie our energy "hogs" (water pump and water heater, for example) to the grid. Our goal will be to move all our energy to sustainable sources down the road, once we've finished with the expense of our initial build.

So, we started stringing wire! The miles (or so it seems) of yellow wire will lead to two breaker boxes: one will draw power from our battery bank, the other from the grid. The GFI outlet in the bathroom has a dedicated wire. The ceiling fans have their wire. The kitchen lighting another wire. Before we string any more lines (for kitchen outlets, bedroom plugs, etc.) we'll tape labels on the existing wires to keep everything straight. 

Bill's done a bit of wiring on houses past. What he doesn't know he looks up in building codes and watches YouTube demos. I have everything to learn. Luckily, I have a patient teacher. Though we're not at the point of putting in plugs yet, Bill tutored me step-by-step through the process so I would have a better understanding of the entire wiring job. Time to get back down there and power things up....