We had a very cold spell this week, which brought about the usual dance of getting our water line through the transition period. It's a very labor-intensive process, as you might imagine. I wanted to detail the events for you in an email, as I think it pertains to all of your interests...Justin with power production and usage, Erik with knowledge of our existing water system and plans for future improvements, and Jim with Taylor management. It's not necessary to reply to this email; it's strictly FYI.
It has been hovering in the high 20's for some time, but on Tuesday afternoon, temps dropped into the low teens. Tyler and I were eating dinner on Tuesday night when we realized that water pressure from our kitchen tap was greatly reduced, which was a big red flag. Tyler suited up and headed up to the west waterbox (east is shut down for the season). As he expected, the onset of cold temperatures had started freezing the margins of Pioneer Creek, and slush coming down the stream had covered and clogged our in-stream intake. Since this waterbox always has a drawdown for our stream engine, the box had rapidly drained. Tyler scraped the slush away from the in-stream intake and the box refilled.
However, that wasn't the end of the night. First, sluggish water pressure is a huge problem, as the water in our lines freezes rapidly if it stops moving. Our new stream engine came with a digital tachometer that allows us to gauge its RPM's, a feature the old system lacked (it's been very helpful for us to be able to actually quantify its production, rather than guessing by ear). Using this tool, we were able to see that the RPM's had dropped down from about 1800-2200 (3+ jets on full, generating 807 watts) to only 860 (less than 1 jet, around 170 watts). We could also feel that some of the hoses going into the engine were vibrating as water moved through them, but others were totally still. These jets are the tightest constriction point on the line, so any slush coming down the line was likely to pile up here.
We immediately set to work on trying to thaw the stream engine hoses to see if that solved the problem. We put hot water bottles on the hoses, and also plugged in a small portable space heater that my family loaned us. Tyler had built an insulating foam box around the stream engine, so the area the space heater needed to heat was very small. We found that the space heater was able to heat the area around the stream engine up to 65 degrees in very short order. However, the price we paid was a significant draw from our batteries (around 800 watts).
Tyler stayed awake the entire night and hiked up to the waterbox about every 20 minutes in single digit temperatures to scrape slush away from the in-stream intake. Meanwhile, a layer of ice was forming over the pool of water where the intake is located. Tyler's job was to keep the intake slush free while that ice sheet formed. Once that protective layer was in place, no more slush would reach the intake, and it would be safe as long as the cold spell lasted (ideally, the whole winter...if we get a warm thaw, we'll have to do this all over again). On each visit, he also removed the waterbox cover, stripped down to a t-shirt, and reached his arm down into the waterbox and removed the wire mesh guard over the opening of our 4" line, knocked off all of the ice forming on this screen, then replaced it. He also used a wire mesh strainer to clear slush out of the waterbox itself.
We watched the entire system very carefully, and were relieved to see the RPMs of the stream engine steadily climb over a period of several hours, and the water pressure in our cabin return to normal.
There was one glitch that night. Around 3 AM (temperatures now about -1 F), the water pressure abruptly fell and the RPM's of the stream engine plummeted. Tyler hurried up to the water line and found that, while the in-stream intake was clear, the waterbox intake was badly clogged. The below-ground culvert the runs from the in-stream intake and the waterbox has a lot of sand and fine sediment in it. Tyler hypothesizes that the earlier draining of the waterbox on Tuesday evening had destabilized this sediment and slush, and that sometime around 3 AM, everything suddenly settled and knocked a large amount of sediment and slush into the waterbox intake. Tyler cleaned it off, but the temporary low pressure undid our progress we'd made toward recovering the system. Tyler continued to revisit the waterbox and hydro shed throughout the night, and by noon on Wednesday, the stream engine RPM's and Taylor Cabin water pressure were nearly back to normal. Tyler had had to go up and maintain the waterbox every 20 minutes for 16 straight hours.
One major concern we'd had was the electric load from the space heater. By morning, it had drawn our batteries down from 100% to 64% capacity. Fortunately, our new solar panels are excellent, and within about 45 minutes of sunlight, the batteries were back at 100%...a huge relief. We've set the space heater next to the stream engine on a timer, so that it runs for 45 minute intervals 4 times each night. This is much less than the constant heating we were doing during the stabilizing period, and it seems to be an acceptable draw for our system. Our solar panels can even recover the energy on cloudy days, but we're still learning to what degree they can recover, and how quickly. We don't know if the space heater is having a salutary effect on the stream engine, or if all the improvement we saw in the RPM's was solely due to Tyler's work keeping the intakes clear. Given the consequences of losing our water line this winter, we didn't want to take chances. We had the space heater on hand to experiment with the efficacy of heating Taylor cabins with electric heat. It seems like this might be too large a draw to do in the cabins (likely needing to run it throughout the day, or using more than one heater), but it certainly came in handy for this job and was far better than using a hair dryer.
We also found that the hoses going into the stream engine that were or were not vibrating when the RPM's were low had not changed when the system recovered. So, that ended up being a red herring.
The weakest part of the system right now is not even on the main line, but is the branch that runs from the main line to the Taylor cabin. This pipe is buried very shallowly in the Taylor yard, and we're not even sure of its location in places. Tyler has placed large piles of hay, mulch, and soil over the area where he believes the pipe to be. He also spent much of the morning today shoveling up the snow from our front yard and moving it onto that line.
We had a scare today when our water pressure suddenly dropped again. Checks of the hydro shed and waterbox showed that everything was working normally, so the main line was not the problem. We eventually figured out that the water line in our yard was safe, but the water filter in our basement was clogged with slush (a new filter Tyler had installed just earlier in the week). We swapped this filter out for a new one and the problem resolved itself.
Here is where things currently stand:
*We're currently experiencing highs in the low 30's and lows in the mid teens.
*The water pool over the in-stream intake is totally frozen over. Tyler has gradually lengthened his time away from it and now only needs to check it twice daily.
*The hydro system is in good working order. Power production from the stream engine is normal, and the batteries are fully recharged by the combination of the stream engine and the solar panels each day. We continue to run the space heater periodically as a precaution.
That's a summary of current events. Thanks for reading!