Deep Six Your Hot Tub

 

Ever since I installed 15 solar panels on my roof last year, I have been geeking out about energy usage and power bills.  I am making much more energy than they predicted from my south facing roof, since the sun is high over the trees in the summer and there are no leaves on them in the winter.  It is really sunny at altitude, and the winter snow albedo makes it even better.  Their models don’t show that stuff.  We make much more power than we use and have no energy bills even though Rocky Mountain Power (RMP) sells me power for 10 cents a kWh and buys it back from me for 5 cents per kWh.  These kinds of replacement power rates were set up at the last minute in the 70’s when Jimmy Carter tried to convince power companies to allow every small power producer to hook up to the grid.  They still must allow that kind of distribution is a more decentralized many producers to many users instead of the one power plant to many customers model.  This should be the goal with every roof, parking lot, road and canal covered with solar panels.  With a windmill at every canon mouth and mountain pass. We need to enable these ‘natural energy’ sources to supplement the dying ‘alternatives’ of coal, oil and gas.

RMP still charges me 18 dollars a month to be on their grid which comes in handy when I get up before the sun and the lights, heat, dishwasher, dryer, espresso, microwave and toaster all work at once.  I do give them tons of noon power for their summer peak demand, when it is worth 20 cents a kWh. The grid is great since I don’t have a big, bad battery, I must use the grid for my battery.  I will eventually get a Chinese electric car I can use as my battery.  Federal Tax Credits were available for solar and wind installations and will be again after the anti-natural energy administration is gone.  Either way the investment is  worth it, the right thing to do, and really cool. 

The amazing thing I found is that my hot tub was using a lot more power than I thought, so I got rid of it after 35 years of loyal service, monthly repairs and weekly use.  We don’t have or need AC yet, so we don’t use much power, but the hot tub surprisingly accounted for at least half of my total power use.  Solar panels or not, that amounts to at least a dollar a day or 400 dollars per year for my little tub.  A big tub or pool can cost up to 1000 dollars a year or (10,000 kWh) or over $100,000 future value dollars over the life of the tub for power.   That is a large carbon and monetary footprint and more power than two efficient houses use. 

Heat transfer from a hot tub is proportional to the difference (delta) in temperatures inside and outside of the tub, so when it is set at 105 degrees and it is 15 degrees below outside that loss is proportionally 120 Joules.  That is 4 times as much energy loss as a similar hot tub in California, where it is always 75 degrees and the loss is only 30 Joules from a tub at 105 degrees.  They can have outdoor hot tubs.  We shouldn’t.  Since most of our power still comes from coal, this is the easiest thing we can do, locally, to make a big dent in our carbon footprint for better air quality and battle climate change. Install rooftop solar, be par of the solution.  Deep Six Your Hot Tub.  Save the planet.