Tag Archives: photovoltaic

December 2019 Solar Production and EV Performance

The additional capacity for my solar photovoltaic array was finally turned on in the middle of December.  For some reason the monitoring software is screwed up—probably because it is tied to the old inverter that is now powering an array for a friend in northeast Iowa.  It is my hope that the issue is resolved in the next few days and I can start comparing total production of the array.

Regardless, I have a decent idea of how I am doing relative to total consumption versus total production using the readout from my bi-directional meter.  For December I ended up using ~208 kWh more than I produced.  Considering that my system was not operational for half of the month I am going to take this as a good sign that I should now produce more than I consume most months out of the year.  In the past December has been one of the worst for solar production.

Knowing my numbers at the beginning of the year it is my estimate that I will be net positive when it comes to total consumption versus total production even including my electricity usage for driving my Nissan Leaf.

For the month of December I drove my Nissan Lead 574.7 miles at an average efficiency of 5.0 miles per kWh.  This translates into a CO2 savings of ~651 pounds compared to driving my prior vehicle assuming an average carbon intensity of electricity from the grid.

For the entire year, I drove my Nissan Leaf ~7,987 miles at an average efficiency of 5.2 miles per kWh.  I think this is a pretty good average efficiency based on what I am seeing on forums and what not.  This represents a savings ~9,119 pounds of CO2 compared to driving my prior vehicle assuming an average carbon intensity of electricity from the grid.  It also represents ~$1,132 savings in fuel costs assuming I draw power from the grid at my residential rate.

The Downside of Snow

Unlike a lot of people I actually like snow.  I like snow so much that I spend my hard earned money to strap wooden sticks to my feet and fling myself down mountainsides covered with the stuff.  Come to think of it, when I describe my ski trips like that it does not sound so sane.  I digress.

The only problem that I have with snow is that it covers up my solar panels.  Like the two inches of snow that fell overnight:

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After last year’s snowy and cold January and February left my panels snow covered and non-productive I decided to come into this winter prepared.  Enter the SnoBroom:

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Okay, the SnoBroom is just the blue foam blade atop the extendable pole.  The extendable pole might be the true star of this story.  It extends to a maximum of 24’ which seemed like a lot right up until I was clearing snow for real:

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With the pole alone I was able to clear the first row of panels and a portion of the second row.  You can see on the closest panels that I spent some time with a step stool to get additional height.  Yes, I was able to nearly clear the panels.  No, I did not fully clear my array.

In the interest of full disclosure I need to come up with a better approach to clearing the array.  Snow, aluminum steps, and a little liquid moisture make for a precarious endeavor.  Practice makes perfect, right?

The other reason I did not push the issue this afternoon is that the temperature is supposed to be nearly 40 degrees with sunny skies tomorrow.  The snow will take care of itself this time.

November 2019 Solar PV and Nissan Leaf EV Performance

November was an ugly month for solar photovoltaic production:

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Why?  My system was disconnected and shut down due to a planned upgrade.  The guys from Moxie Solar installed an additional 8 panels and the attendant “balance of system” components like a new grid tie inverter.  The 8 additional panels represent an approximate 62% increase in nameplate capacity for my system.  Given the orientation and installation location are virtually the same as the previous 16 panels I expect to see an approximate 62% increase in solar production once the array is powered up.

This has to be one of the most frustrating parts of a solar installation.  The rooftop install and other system components were done in a little more than a working day.  The city inspection was done in about fifteen minutes and done a few days after installation.  The permission to operate and the simple act of flipping the switch?  I am still waiting.

See most of those zero production days in the last week of November?  That is the cost of waiting for someone to come over from the electric utility and watch a person from the solar installer flip a switch.   It is like a bad anecdote about union rules from the 1980s.  Soon…the switch will be flipped soon.

This might also be the last month for a while where I seen an average of over 5 miles per kilowatt hour in my Nissan Leaf.  For the month I drove a total of 619 miles that used 123.8 kWh of electricity at an average efficiency of 5.0 miles per kWh.  At an average carbon intensity, I avoided emitting ~702 pounds of CO2.

What November really taught me is that cold weather kind of sucks for an EV.  My particular Nissan Leaf is not equipped with the heat pump, so it relies on a resistive heater to provide any level of defrost in cold weather.  Most of the time my trips are short enough that I just deal with a cold cabin while the heated seat and steering wheel keep me cozy.  Put three passengers in the car and the windows start to fog up pretty quick with hot breath.  There is nothing so dispiriting as watching the guess-o-meter drop by 30% or more when you turn on the heat.

It is not enough to dissuade me from recommending an EV in general or an older Nissan Leaf in particular.  There is something to be said for taking advantage of a market dynamic like extreme depreciation.  You can have your Tesla Model 3.  I will take my solar panels, Nissan Leaf, and decarbonized home to the bank every day.

The Financial Math Behind Decarbonization

What if I told you that for the price of a base model Tesla Model 3—good luck actually finding one—you could decarbonize your household?

What if I told you that this is not a thought exercise but an examination of steps already taken?

Are you ready?

The price for base Tesla Model 3 is ~$35,000.  That is the price assuming that you can actually purchase the so-called “standard range” model and before any applicable tax credits.  For the purposes of this discussion I am going to leave tax credits aside for the time being.  So, we are working with a starting price of $35,000.

For that price you get an electric vehicle that has to draw power from the grid, which depending upon your locale and power company may support coal fired electricity.  It may also support fracking for natural gas or the nuclear power energy, assuming any of that industry remains in your region.

What else could you do with that $35,000?

Over the course of the past two and half years I have installed solar photovoltaic panels on my roof in two phases.  Why two phases?  Initially, my power company would only allow my roof mounted solar photovoltaic array to exceed my annual consumption—based on average expected production—by ~10% or so.  Considering how little electricity my household used in comparison to the average this worked out to a system of 4.64 kWh.  This initial phase cost me ~$11,000 before tax credits at the state and federal level.

In the past month I added ~62% more capacity to my existing solar photovoltaic array at a cost of ~$7,500.  In the past year I added an electric vehicle to the mix, which has upped my household consumption, in addition to a few winter months in 2019 where my prior panels were covered under deep snow curtailing production.  We also forgot to turn off a garage heater, which ran up the electric bill in February.  All told these changes goosed our consumption just enough to allow me to install an additional eight panels on my roof.

As it stands right now the photovoltaic array on my roof has a nameplate capacity of 7.52 kWh.  This was complete at a total cost of ~$18,500 before any tax credits.  Remember, we are leaving tax credits aside for the moment.  Assuming my household usage patterns hold—including one electric vehicle—this system will produce more than 100% of my household’s electricity requirements for the year.  The estimated excess production should allow me to replace my natural gas water heater with an electric air source heat pump model further reducing my household requirements for fossil fuels.  With the water heater replaced in the next year my household will only use natural gas for the forced air furnace in the colder months.  Trust me, I am looking at options to replace that as well.

What about the electric vehicle?  This is where the power of the market and a realistic assessment of one’s needs come into play.

A Tesla Model 3 is a fine automobile.  Dollar for dollar, it may be the best vehicle on the market right now when one considers its relative performance and environmental bona fides.  However, it still costs $35,000.

In January of this year I purchased a used Nissan Leaf for ~$11,500.  The Leaf had ~33K miles on the odometer, but the battery was in great condition being that the 2015 and later model years utilized an updated architecture that corrected some of the prior model years’ most glaring problems.  A purchase price of more than eleven thousand dollars might sound like a lot, but this was a car that retailed for more than $30,000 when new.  Losing two thirds of car’s value without high mileage is crazy town.  Or, good for the person who can take advantage.

If one can live with a lesser range, one can take advantage of the market punishing these older EVs for not being up to Tesla’s newer standards.  If one drives in town, for the most part, there is no disadvantage.  In almost a year of daily driving I have had just one instance of the range “guess-o-meter” dropping below ten miles remaining and I have never experienced the indignity of “turtle mode.”

How does this all add up?  Total cost for me to purchase an EV to replace all of my daily driver miles and enough solar photovoltaic capacity to power me entire household, including EV electricity requirements, was less than $30,000 before any tax incentives.  Compared to a $35K Tesla Model 3 I would say that I ended up in a better place.  Five thousand or so dollars better, mind you.

This is not to diminish the decision of someone purchasing a Tesla or any other EV.  Rather, it is to illustrate that there is an alternative path to decarbonization that is neither as expensive as portrayed by many and without any appreciable downsides.

The future is now.

This is What the Future Looks Like

Last week the installers from Moxie Solar completed the installation of eight additional solar photovoltaic panels on my west facing roof and the attendant upgrades to the electrical system (e.g. larger inverter).

Here is what 62% additional solar capacity looks like from the road:

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See anything?  That is right, you do not see anything out of the ordinary save for a standard suburban house.

Here is what that same additional solar capacity looks like from the west side of the house:

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This is what the future looks like.  Twenty four panels—sixteen 290W panels and eight 360W panels—producing green electricity every time the sun sends its rays our way.  These panels do their thing every day without nary a thought or action from me.  Silent and motionless these panels produce clean electricity.  This solar array will produce more than 100% of my household’s electricity needs including an electric vehicle.

If this is not the future than I have no idea of what will come to pass.

Friday Linkage 11/8/2019

Did Trump suffer the greatest defeat of all time in Kentucky?  Not so much. He was in that state to rally for a horrible candidate who ended up losing by a razor thin margin.  However, Trump is a loser nonetheless. And a clown.

On to the links…

It’s Official: Trump Just Started the Process to Formally Pull Out of the Paris Climate Accords—This is where we are now.  In one year we have the best chance and maybe our only chance to stop this madness.

EPA to Ease Restrictions on How Coal Plants Store Toxic Waste—This is what you get with the Trump administration.  Coal companies want to pollute without regard for anything.  Coal companies get what they want because they are sucking up to Trump and will be with him until the end.

Why Restoring Nature is so Important to Limiting Climate Change—Restoration is the concept we need to be fighting for right now.  If we can restore forests, wetlands, bayous, grasslands, and what not we have a chance.

How To Reach U.S. Net Zero Emissions By 2050: Decarbonizing Industry—Transportation gets all of the attention because cars are part of our national psyche, but industry is a big player in terms of emissions.  Just reducing emissions by concrete and steel producers would do a lot to put us on the path of net zero emissions.

How America Can Reach Net Zero Emissions By 2050: Decarbonizing Buildings—There is a lot of progress that can be made by figuring out how our buildings are using energy and fossil fuels.

Race Heats Up For Title Of Cheapest Solar Energy In The World—This is a race to the bottom that you want to participate in as much as possible.  How is coal and, perhaps, natural gas going to compete with solar at $0.0164 or lower per kWh?

Huge Battery Investments Drop Energy-Storage Costs Faster Than Expected, Threatening Natural Gas—Peaker plants are going to be replaced by big batteries.  Like replacing coal, these batteries are going to replace the most inefficient and polluting natural gas electricity sources.  Overbuilding renewables and building out a level of storage is how we beat the “duck curve.”

Giant Water Battery Cuts University’s Energy Costs by $100 Million Over Next 25 Years—This is so low tech and cool at the same time.  Why can’t this type of solution be deployed in places like California and Arizona?  Oh wait, it could.

New Lithium Ion Battery Design Could Allow Electric Vehicles to Be Charged in Ten Minutes—This is how EVs get better without a major breakthrough in battery technology.  Improve the charging, increase the efficiency of the components, etc.

Can ‘Nests’ and Eco Bikes Reduce the Environmental Impact of Parcel Delivery in Cities?

—Bikes are amazing and if we are going to insist on buying everything from Amazon at the very least the delivery can be eco-friendly.

Sydney Hints At Electrification Of 8,000 Buses—We are never going to build out rail networks in our cities that are built for automobiles using surface streets.  However, as density increases we can utilize electric buses to utilize the existing infrastructure in a better way.

Backcountry.com Breaks its Silence Amid Trademark Lawsuit Controversy to Apologize and Aay “We made a mistake”–The first rule of being an outdoor manufacturer or retailer should be “Don’t be a dick.”  No one was confusing someone talking about backcountry skiing with an internet retailer.

October 2019 Solar Production and EV Performance

October 2019 was an okay month for solar production:

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As you can see, my solar array exceeded the production of 2017 but fell short of what was produced in 2018.  Those are the breaks.  All in, my household ended up down ~229 kWh.

Granted, a lot of this delta between consumption and production can be accounted for by the Nissan Leaf sitting in my garage.  For the month of October I drove 900.3 miles at an average efficiency of 5.4 miles per kWh.  Total electricity consumption to drive my EV was ~167 kWh.  This represents an approximate savings of 1,034 pounds of CO2 versus driving my prior vehicle.

For the year I have driven 6,794 miles with an average efficiency of 5.3 miles per kWh.  Assuming all of the electricity I have used comes from the grid at an average carbon intensity for my region I have saved ~7,767 pounds of CO2 from being emitted.

What is really a good sign is that I should really be in the black when it comes to consumption versus production within a month or so.  My local electric cooperative approved my revised interconnection agreement and an additional 8 360 watt solar panels are waiting to be installed.  A weekend with snow has kind of messed up everyone’s schedule around these parts so I am just waiting for the phone call from the installers.  Any day now.

An extra 62% production capacity will put me well above my consumption numbers, including my EV’s needs and a few electrification projects I have pending, for the foreseeable future.  For the year I estimate that I would be ahead of consumption by 1,858 kWh assuming similar weather patterns.  That is a lot of cushion to further decarbonize my household.