Tag Archives: PV

This is What the Future Looks Like

People frequently ask me what I think the future looks like.  Rarely do I provide a coherent answer because what I think will happen is constantly changing based on the conditions of the day.  There do exist some constants, however, and solar power is one of those constants.

Why?  For one, it is easy.  Once the panels are installed your array will just sit on your roof producing electricity regardless of what you do.  When you go to work the panels produce electricity.  When you go on vacation the panels produce electricity.  It is the ultimate in “set it and forget it” environmentally beneficial behaviors.

Second, you can see the impact at a household level.  If my utility purchased electricity produced by wind turbines I have no real concept of what that means to me.  Was 15% of my electricity produced by the wind?  More?  Less?  However, with solar panels installed you get a very local idea of how much energy you have produced versus how much you have consumed.  Witness this portion of my latest utility bill:

Electricity Usage House September.png

Notice the lack of green bars from April through August?  That signifies my solar array produced all or more of the electricity that I consumed during that period.  Sometimes my math and the utility company’s math will not align because billing periods do not align with calendar months but the general outlines agree.

Now, imagine approximately 60% more solar photovoltaic capacity being added to this chart.  The contract has been signed, the check has been sent, the plans have been approved, and the panels are waiting in a local warehouse for my system expansion.  I am just waiting to hear when the installers are scheduled to make it happen.

This is what the future looks like.

Advertisements

A Great Month for Solar Production, Electricity Consumption, and EV Efficiency

At last!  In August 2019 my solar photovoltaic array produced more than the same month in prior years.  I was somewhat consigned to a reality where my best days of solar production were behind me, but August came to the rescue:

Image-1 (4)

All in, my household ended up 179 kWh “up” in terms of electricity production minus consumption.  Remember, this includes all of my EV miles as well.  For the year I am creeping back toward being even in terms of production minus consumption after some awful months in the dead of winter.  During that period of time my solar array was covered in nearly a foot of wind driven snow and our electricity usage was high due to crazy low temperatures.  Normally August is a heavy month for air conditioning use.  Our HVAC system has been idle since the first week of month.

For the month of August my total miles driven in the Nissan Leaf was depressed by not being home for a little more than a week.  In the end I drove 531.2 miles at an average efficiency of 6 miles per kWh.  Compared to my truck and assuming power is drawn from the electricity grid, I saved ~620 pounds of carbon dioxide from entering the atmosphere.

Since bringing the Nissan Leaf home I have driven a total of 5,138 miles and save 5,854 pounds of carbon dioxide from being released.  Using the most conservative method of calculating savings—which assumes all electricity comes from the grid as opposed to my solar panels—I have saved just under $727 in fuel costs alone.

June 2019 Solar was Back on Track and EV Miles were Extra Efficient

June was a better month for solar production:

share_image

Over the course of the entire month my household ended up ~150 kWh (consumption minus production), including all of my EV charging for that same period as I did not use any public chargers.  With at least eight more panels being installed on my roof this summer I am going to be seeing a lot more months with excess production.  Every kilowatt hour that I produce from my solar array is like a nail in the coffin for coal.

The excess production in June was a little artificial because we were on the road for more than a week.  With no air conditioning running it is to be expected that we would run a surplus.  June was also fairly cool with a corresponding lack of need to deploy air conditioning.  The last few days of the month were a reminder that summer in Iowa is a hot and sticky affair.  I am talking temperatures exceeding 90 degrees and humidity levels exceeding 90%.  If there was ever a time where I did not want to come home from the mountains this was that time.

For June I drove my Nissan Leaf a total of ~555 miles at an average efficiency of 5.9 miles per kWh.  This is my best number by far, in terms of efficiency, and makes me wonder if I can nurse my way to a figure over 6 miles per kWh in July.  For the period I saved ~646 pounds of C02 being emitted assuming that my charging came via the grid at an average carbon intensity.

You may ask how I can be ahead in terms of energy production yet still account for some level of carbon intensity for my electric vehicle.  Unfortunately, my photovoltaic array’s production occurs when I am not charging my EV which usually happens at night.  Therefore, to run my Nissan Leaf I am utilizing grid electricity.  It’s a little like keeping two sets of books for the same business.

May Showers Dominate Solar Production and Electric Vehicle Efficiency is Stable

May was a rainy month in eastern Iowa.  How rainy?  It rained for twice the number of hours in May and three times the usual rainfall hit the ground.  Things were really wet.  Like the “ground is a sopping wet sponge” wet.  It had an impact on May’s solar production:

share_image__03_Jun_2019__07-35-25

Now, just over 542 kWh of clean, green solar electricity is not bad.  It is down about 80 kWh from the same month the prior year.

All in all, my household ended up about 10 kWh ahead of consumption for the month of May including home charging of the Nissan Leaf.  When you can drive all month and live in house with modern amenities all powered by the sun that is considered a win.  Sometimes I just feel like I am living in the future.

For the month I drove 937.4 miles in my Nissan Leaf at an average efficiency of 5.5 miles per kilowatt hour.  This beats my efficiency the prior month by 0.1 miles per kilowatt hour.  This saved ~1,080 pounds of carbon dioxide emissions versus my prior vehicle assuming that I charged using grid electricity, which in Iowa averages about 1 pound of CO2 per kWh.  As noted above, I actually ended the month ahead of my consumption so the emission savings were probably higher.

It does not seem like a big win in terms of efficiency.  However, there are two round trips to Iowa City that totaled almost 140 miles of driving at highway speeds.  For anyone who has driven a Nissan Leaf there is a moment of dread the first time that you get the little car up to 60 miles per hour or more and watch your efficiency drop like a stone in freefall.

The trick is to minimize interstate highway type driving in favor of more sedate state or county highway driving.  That is to say, drive 55 miles per hour as opposed to the 70 miles per hour or more on the interstate.  It takes a little longer, sure, but there is something really peaceful cruising along with the windows down and the silence of an electric vehicle drivetrain.

It also helps to have access to public charging at the midpoint of your trip.  In Iowa City there are ChargePoint facilities available in several public parking ramps.  You pay for parking (first hour is free and a $1 per hour for any additional time) and the charging is free as long as you have a ChargePoint account.  My Leaf is equipped with a standard Level 2 charging port so it can accept, at most, 3.3 kWh of electricity per hour of charge.  It is not a lot for the ninety minutes or so that my errands in Iowa City take, but it provides a margin of safety for the trip home that eases any potential range anxiety.

These trips have gotten me thinking about electric vehicles and range.  Maybe the issue is not absolute range, as in 235 miles of range when fully charged, but rather the ability to gain a lot of range in a short period of time, as in 80% battery charge in 30 minutes.  If I was able to regain more than three quarters of my vehicle’s charge in less time than it takes to make a quick trip into Costco that would change my route calculations considerably.  Also, if more public charging facilities were available at destinations that might also change behavior.

Do I spend a little more time in downtown Iowa City because I am charging my Nissan Leaf?  Probably.  Think about that from an economic development standpoint.

Cracking the Electric Vehicle and Solar Photovoltaic Code in April

April felt like the month where I cracked the code on this whole electric vehicle thing.  How so?  After averaging 5.0 miles per kilowatt hour (kWh) in March and considerable less in the prior two months I ended April at an average of 5.4 miles per kWh.  Over the course of ~630 miles of driving I saved ~724 pounds of carbon dioxide emissions compared with my prior ICE vehicle.

Since mid-January when I acquired my used Nissan Leaf, I have driven a total of ~2,214 miles and saved ~2,456 pounds of carbon dioxide.  Not to mention saving ~$230 in fuel costs, which is a number that is sure to go up as fuel costs are creeping up here in eastern Iowa along with the spring time temperatures.

The story gets even better when you factor in April’s solar production:

Image-1 (2)

The numbers are not dramatic in and of themselves.  However, for the month—including the electricity that I used to “fuel” my EV—I produced ~95 kWh in excess of my needs.  For the month of April my house and my car were more than fueled by the sun.  That is the future.

Imagine what things will be like when I increase the generating capacity of my solar array by almost 60%.  Based on my calculations that will allow for more than 15,000 miles of electric driving per year which should cover both my and my wife’s commuting miles in town.

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:

Image-1 (1)

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.