Monday, January 27, 2014


As the Salt Lake Valley fills with increasingly toxic levels of PM2.5 consider the following:

Some numbers for you:

Over the last 7 days we have produced approx. 140kWh of energy from our solar array, or about 20 kilowatt hours per day.  This is using #17 230watt panels on the southern aspect of our roof.  These have been sunny days for sure, but it is also January.  In an average day we use between 5-10kWh of electrical energy for our household needs.  We just added an all-electric vehicle (2013 Nissan Leaf) which will require on average 6-10kWh per day for our transportation needs.  This is between $0.60 and $1.00 per day (at 10cents per kWh) to charge the vehicle (converting this to miles per gallon equivalents yields approx. 115mpg, or 129mpg with city driving).  A Nissan Leaf gets approx. 3 miles per kWh (with 0 emissions).

This week I accumulated 7000meters of vertical climbing via running and skiing.  Taking my approximately 70kg body (optimistic) to this height would yield 1.33kWh of potential energy.

Over the course of this approximately 15 hour training load I burned a rough 9,000kcal, or 37,656,000J (or 90 packets of Gu for you crazy ultra runners) which is equivalent to 10.5kWh of energy.  Translating this to flat running energy expenditure would yield somewhere in the vicinity of 90 miles, or 8.6 miles per kWh.

Some simple math shows that if you could harness the energy efficiency of my Nissan Leaf in my 70kg body (instead of the 1600kg vehicle) I would be able to travel 68.6miles per kWh, or 720 miles with the same 90 Gu equivalents of caloric burn.  Shit, even the paleo diet won't make you that efficient (sorry Matt Hart).

Some other, perhaps more relevant numbers for you:

Net cost of all materials and installation after accounting for the Rocky Mountain Power Solar Incentive Program Rebate +  State Rebate + Federal Rebate  = Approx. $0.00.

Savings per month on electric bill = Approx. $30.00

Savings per month on gasoline = Approx. $250.00

Cost to lease a 2013 Nissan Leaf = Approx. $250/month.

PV racking

Crucial help from Jared and Billy.  Jared was the inspiration for the project and an enormous help in getting this off the ground.

#17 Canadian Solar panels with Enphase M190 microinverters.

Photovoltaic family.