Tag Archives: PV

Spring has Sprung: March 2019 Solar Production and EV Stats

Can you tell the exact time when the snow finally melted in Iowa and it began to feel like spring?  I will give you one guess looking at the image below:

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It was like someone opened a door and spring rushed in looking for treats like a good boy.  I said it last year and I will say it again this year…I need to get a roof rake so that I can brush the snow off when it refuses to slide off my solar panels.  The way these things go it will probably be a very light snow year next season and the roof rake will sit in the garage unused for months.

It is my hope that April sees a production number on par with the prior year as the previous few months have really been mediocre in terms of solar production.  There is something ironic about getting an electric vehicle at the same time that my solar production fell off a cliff.  Oh well.

Speaking of the Nissan Leaf it also had a month when it became obvious that the weather had turned.  I drove 603.4 miles at an average efficiency of 5.0 miles per kWh.  This compares with average efficiencies of 3.6 and 3.9 miles per kWh in January and February respectively.

Two factors played into this efficiency increase: warmer weather that resulted in less use of the resistive heater and better knowledge of how to wring out mileage from the vehicle.  It is kind of amazing how you can optimize your driving along a route without resorting to any crazy hypermiling or vehicle modification. This is the kind of improvement that makes me wonder how much efficiency we can wring out of the transportation system without having to resort to draconian measures.

Over the course of the past two and a half months I have driven a total of 1583.6 miles in my Nissan Leaf.  That has saved 1731.9 pound of CO2 versus my prior vehicle and cost a total of $49.34.  The emissions and cost numbers are based on me using grid electricity for the entirety.

As an aside, I utilized a public charger for the first time this month.  In practical terms it was super easy.  I pulled up to one of the two spots at my place of work, tapped my Chargepoint RFID keycard, and got to charging.  There has been a lot of talk about infrastructure for charging and how it impacts the widespread adoption of EVs.  In my experience, the publicly available charging infrastructure is not the major hurdle to adoption for a lot of people.  Unlike urban areas, the suburban area that I live in is rife with attached garages where people can charge their vehicle at home overnight.  Within line of sight of my garage are two houses with Tesla Model 3s and in conversations with the owners I have found that they also rarely, if ever, utilize public chargers, including Tesla’s vaunted Supercharger.  It is just not necessary for the majority of driving that takes place in an average day.  Heck, I only used the charger at work to ensure that my Chargepoint card worked so that I could take my Leaf down to Iowa City in the summer.


Solar Photovoltaic and Electric Vehicle Report February 2019

Something happens when you get hit with a polar vortex, twice as much snow as normal in February, and several ice storms depositing a nice frozen layer over everything.  That something is that your solar array’s production stinks:

Feb 2019 solart

I thought January 2019 was bad, but it looks like February 2019 is a bad month for solar photovoltaic production as well.

Having a roof rake might have helped some, but the quantities of snow and ice were pretty extreme at times this month.  I am just hoping that March is a little warmer—no chance of that over the course of the next week—and things will clear up the natural way.

On the other hand, I have moved up the learning curve with regards to operating my Nissan Leaf.  This month I drive a total of 627.7 miles in the EV at an average efficiency of 3.9 miles per kWh.  This is an improvement of 0.2 miles per kWh over the driving that I did in January.

This month’s mileage, comparing it to the environmental impact of my Ford F-150, prevented the emission of 676 pounds of carbon dioxide.  In less than 1,000 miles of driving I have prevented the emission of over 1,048 pounds of carbon dioxide.  I have also saved over $97 in fuel costs compared with my prior vehicle.

I have decided to combine the monthly reporting of these two aspects of decarbonizing my household because they are intimately related.  What electricity produced by my solar array that is not consumed by my household needs is funneled to my electric vehicle.  As it stands today my array will not produce enough electricity on an annual basis to satisfy both my household’s needs and my electric vehicle’s needs.  To remedy that situation I have an estimated in hand for adding a little more than 50% to my array’s capacity to produce enough electricity to satisfy more than 12,000 miles per year of driving.

The timeframe for adding solar has not been decided and it may not happen this year.  Paying cash for my Nissan Leaf was a fairly major expense just a week into the new year, so that has to be considered.  However, with tax credits set to decline or expire depending upon the political whims of Republicans in my state I may jump on the project sooner rather than later.

January 2019 Solar got Whacked by Snow and a Polar Vortex

Winter returned to eastern Iowa in a big way in January.  Want to guess when it got all wintry up in this house?  Check out the chart and tell me:


Yep, you can see when the nearly foot of snow covered my solar panels.  Normally the snow will slide off with a few warmer days.  Heck, even when it is still pretty cold the sun can make enough of a difference to clear the panels.

However, when the polar vortex comes along with some new snow the panels on top of my garage remain covered.  Things should warm up this weekend—it might be sixty five degrees warmer this weekend versus Wednesday—and the snow should clear.

Just over 68 kWh of solar electricity for a month is the lowest production number in my system’s brief history.  It is also less than half the production from the same month last year.  It goes to show that I might need to invest in one of those soft rubber roof rakes to clear my panels in times of inclement weather.  Especially if I am going to expand my system by more than 50% to account for the electricity use of my Nissan Leaf.

More to come on the solar expansion very soon.  I promise.

Short December Days Lead to Low Solar Output


December 21st was the shortest day of 2018.   Given the short days of December solar output is usually fairly dismal:

December 2018

A monthly total of ~157 kWh is roughly on par with the prior year’s production, so it is a trend that December basically sucks for solar.  At least it will get better in January as the days get longer!

On a related note, I am a few days away from signing on the dotted line for a used Nissan Leaf EV.  The next step is to contact the good people at Moxie Solar, the installers of my current solar array, to see about expanding my system.  In order to produce enough electricity for my anticipated driving I will need to install at least 8 290 watt panels but I would like to install anywhere from 12 to 14 290 watt panels.  We shall see what they say.

Until next time.


Over 700 kWh of Solar Electricity in July

July 2018 was the best month ever for my house’s solar photovoltaic array:

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Approximately 742 kWh of renewable energy from the roof of my garage seems like magic.  I still think there is some black magic going on in those panels that turns sunlight into electricity, but I also still like Harry Potter so maybe magic is my thing.

Even with some days of fairly heavy air conditioning use when the humidity climbed along with the temperature, I still managed to produce ~250 kWh more this month than I consumed.  In total, since my system was turned on at the end of August I am up over 700 kWh when I compare production versus consumption.

Here’s the thing, with a middling sized solar array—just 4.64 kW on a 270 degree azimuth facing roof—generates more than 100% of the electricity that I use in a large-ish American suburban home.  It is my contention that this shows we can move to 100% renewable energy a lot easier than anyone thinks.  A combination of renewable energy deployment, efficiency, and comment sense conservation can get us there with little sacrifice.  For everyone who says that it cannot be done I welcome you to have a discussion with me about the topic.

Here’s to hoping that August and September can come in big to build a buffer against the gloomy winter months.

Back in Black…Electricity Wise

A good month or so of solar photovoltaic production and a nine day vacation put me back in the black in terms of energy production and consumption:


Eighty two kilowatt hours of clean, green solar electricity production above my household consumption to be specific.

As you notice from the image above my bill is not zero or even net positive.  Why?  The dreaded facility charge or connection fee.  What is this?  It is the fee charged by your electricity provider for the use of the grid regardless of your electricity consumption or, in my case, production.

Now, the grid essentially acts as my battery since I have a purely grid-tied solar system.  It does not seem like a heavy burden to bear per month for the security of having electricity on demand.  However, in some states—here’s looking at you Arizona—legislators, hand in hand with their energy company lobbyists, are pursuing fees for connecting solar systems and higher facility charges in general to supposedly offset the costs incurred by these systems being active.  Some states have proposed that solar system owners pay an extra per kilowatt hour fee for each kilowatt hour that they draw from the grid.

This all seems fine and dandy to the people running electric utilities, but it may end up creating the conditions for a death spiral.  As costs for battery storage decrease and solar systems proliferate households may choose to sever their connection to the grid entirely.  In high cost or low reliability locations this is already happening.  As increasing numbers of households leave the grid the existing infrastructure is supported by fewer rate payers increasing the individual household’s share of the costs.  Costs go up and the incentive to sever ties to the grid increases thus more households make the leap.

None of this will occur overnight, so to speak, but the conditions are becoming increasingly favorable for such a transition to take place.


March Brought Over 400 kWh of Solar Electricity

For the month of March my solar photovoltaic system produced just a hair over 424 kWh of electricity, which stands as my second best full month since my system went active in the last week of August 2017.  A few things stand out from the month:

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Notice the two major dips in production?  That is the impact of some spring snowfall that covered my panels under at least six inches of heavy, wet snow.  It just goes to show the potential value of a snow rake in upping my production next winter.

The other thing that is interesting, but is not something readily apparent in the production chart, is that the month was just generally more productive each day.  Granted, the days are longer in March.  However, I think that there is something to be said for the intensity of the solar radiation being higher as we head into spring.  The winter months in Iowa are known for being heavily cloud covered and this reduces the overall productivity of the solar system.

The last week, as the sun stays bright until after 7:00 PM, I have noticed that the system is producing well in excess of 3 kWh into the late afternoon/early evening.  This bodes well for the coming summer months when the array will be getting hit with the sun fairly heavily from noon until sunset.