Tuesday, May 19, 2020

Off-grid Solar and Radiant In-floor Heating

This is a home that I installed an off-grid power system at near Elkins, WV.  I was "in the neighborhood" on Sunday and took a couple of snaps.
Red Creek Construction built the home in 2018/19.  It's a story-and-a-half on top of a full basement.  The electronics and batteries are in the basement.  Having adequate mechanical space for batteries and electronics is very important with an off-grid system.  This particular system uses most of a 8' X 12' room.

The solar PV array on the roof was sized to power the home with little or no assistance from the Kohler 14K generator.  There are twenty-three 295-watt SolarWorld PV modules.

The house has in-floor radiant heating and a deep deep well.  While the radiant system uses a LP boiler to heat the water it is also dependent on a series of electric pumps to circulate the water to the different heating zones.  The individual pumps are small in terms of their power draw, but the combined use of all the pumps running throughout a winter day can add up to a significant electrical load.  On similar homes with in-floor heat the daily energy consumption in the winter can be double what it is in the summer months.

Here the solar is sized to handle the full load in winter when heating demand is at its peak and solar exposure is at a minimum.  The upshot is that the shoulder and summer months enjoy an excess of energy production and the homeowners report that it is not uncommon for the battery bank to be fully re-charged before noon.

Monday, April 27, 2020

Electric Greg - Movie Short for Those Curious About Electric Cars

My couty's development director turned me on to a short film focused on one adventure athlete's personal challenge of transitioning to the exclusive use of an electric vehicle.  It's about 20 minutes in length and was a fun watch for our family.

Monday, April 13, 2020

Charging an Electric Vehicle with Solar - Pendleton County, WV

(Chevy Bolt EV getting a fill-up at home from a ClipperCreek Level II Charger)

Electric Vehicle (EV) charging has a new boost from a re-instated tax incentive that offers a 30% federal tax credit to businesses and homeowners who install EV charging stations before December 31, 2020.

The tax credit legislation also retroactively applies to EV chargers installed in 2017, 2018 and 2019.  To read a bit more about the legislation and find the IRS form you can take a look at pluginamerica.org

Solar also continues to enjoy an exceptional tax credit through 2020 at a rate of 26% of the installed cost.


This particular solar installation powers the charging of a Chevy Bolt as well as the energy needs of the classic Sears kit home in the background.  The system is grid-tied for net-metering with  MonPower, the local utility.

Friday, February 14, 2020

Solar in the Woods -Grantsville, MD

This 4.32-kW solar PV system was installed in 2011.  At that time, an arc of trees had to be cleared away from the garage to ensure that the system would operate at its peak. The house has recently been for sale and the owners asked a friend to fly some drone imagery for the sale advertisement. 

The image below shows the extent to which the surrounding forest was cleared to allow for shade-free operation of the solar.  I think it's helpful to see this birds-eye view years later as it illustrates the cleared area, but also shows shadows from the trees that were left.

The garage is south facing and I'd expect the image was captured close to noon.  By providing a clear skyview for their solar panels these customers were able to meet their goal of making more electricity than they required.  They are moving to a new home built to a Passivhaus standard where they expect to also be net-zero.

Thursday, April 5, 2018

Still Hollow Spirits: Solar 'Shine

The Parsons Advocate ran a nice article this week about our local distillery, Still Hollow Spirits.  Based in Job, WV and taking advantage of an excellent spring water source, Still Hollow produced its first batch of corn whiskey just in time for the holiday season.  They rapidly sold out of batch #1.
Construction of the distillery building included the installation of a 9.6-kW solar PV array.  After  a year of operation the solar has produced more energy than consumed by the distillery leaving Still Hollow with a net metering credit.  Clean energy, clean water and clean living!

The solar PV array consists of thirty-two SolarWorld  300-watt modules (MADE IN THE USA!).  Two SMA SunnyBoy SB-series inverters are used to convert and connect the solar power to the utility grid.  The system is designed for net metering with MonPower.

Still Hollow Spirits is a really nice place to visit.  It is an easy drive from Seneca Rocks, Canaan Valley, Spruce Knob and Elkins, WV.  The distillery is open for tastings and tours.  The best place to get in touch and check on their hours is through their Facebook page.

Friday, March 23, 2018

Batteries in the Spotlight at 2018 Niagara NABCEP Solar Conference


The number of battery vendors at this year's NABCEP solar professionals conference was noteworthy as was the introduction of Morningstar's soon to be released 48V battery-based 4K inverter lineup.  The emphasis on battery-based direct current systems was ironic, given the location was Niagara; well known as the place where modern utility-scale alternating current had its debut.  Mr. Edison would have been pleased.

One observation frequently made was that the solar industry, after years of being dominated by battery-less grid-interactive systems, is now seeing its future closely aligned to battery storage systems.

Sonnen 4-kW Battery System for Backup and Load Shaving (includes an 8-kW Outback Inverter)

Lithium battery manufacturers present included Hawaii's Blue Planet, Germany's Sonnen and Vancouver's Discover AES.  I am frequently asked about lithium alternatives to lead-acid batteries which have been the mainstay of off-grid and backup systems for years.  In short, the technology is here, but any adopter may be on the bleeding edge as systems have a steeper entry cost and an unproven track record. Could be good, though!

Something else that could be good is the new 4-kW 48V inverter from Morningstar.  This is a company that has built a really nice line of solar charge controllers over the last 25-years.  I've used their PWM and MPPT equipment on both solar and microhydro systems.  This is their first "whole-house" or big inverter.  Notable among the features include:
  • 18W idle loss (this is way low - like 47% lower than an Outback FXR unit)
  • 120V or 120/240V
  • Integrated control panel
  • Space for six relay blocks (ie, generator start, vent fan turn on, on/off loads, etc...)
  • No cooling fan
  • Dummy-proof bypass switch
  • Breaker panel for code compliant installations 

 Morningstar's 4-kW Inverter with the Covers Removed

Friday, January 19, 2018

Keeping it Neat: Off-grid Samlex Inverter Installation w/ E-Panel

Chuck finalizing the installation of six SolarWorld 300W solar PV modules.  The Samlex EVO4024 and battery bank are housed inside this nice pre-built shed.

Samlex wasn't even on my radar until I got a call late last summer from a couple who had purchased a Samlex EVO4024 inverter for their off-grid home near Belington, WV.  Up to that point I had mostly used Outback and Schneider/Xantrex brand equipment for off-grid jobs.  Chuck and Deb who had this Samlex unit had also purchased a bank of Trojan batteries and a Generac 15kW EcoGen generator.  When they called they were in search of someone who could pull all the pieces together into a functioning off-grid electrical system.
Part of pulling the pieces together was the addition of a MidNite Solar E-Panel.  Not to get too technical about things, but I find it's common for folks who source their own equipment to overlook key switch gear and enclosures that ultimately make a system safe, serviceable and code compliant.
Looking at the EVO4024 for the first time I was cognizant that the unit, as it is sold, could not alone yield a polished final installation.  Basically, it was lacking a cover for the large DC cables that connect the inverter back to the batteries.  This is fairly common among inverter manufactures, but does not yield a safe or code compliant installation (it also leaves things looking sloppy).
Many off-grid inverter manufacturers offer units without any enclosure to protect the DC cabling.  Most, however, do offer an optional enclosure that can be purchased separately and is purpose built to be paired with their inverter equipment.  These optional enclosures commonly include space for disconnects and breakers that protect the wires and the electronics in the system.  Samlex does not offer something like this and I was a little perplexed after I first gave their website a once over and concluded that I would have to look elsewhere.

The big dark blue box is the EVO4024 inverter.  It is mounted to the E-Panel which is affixed to the wall.  The MidNite E-Panel includes the gray portion below the inverter (this limits access to those DC cables).  The small black "thermostat" at the right is the control panel for the inverter.  The larger black piece of electronics is an Outback FM80 solar charge controller.

MidNite Solar would win an award as the most creative manufacturer of solar related enclosures and electronics equipment.  They were the next place I looked for an enclosure that could be paired with the EVO4024 inverter and sure enough they had something tailor-made to fit!  MidNite Solar has been manufacturing E-Panels for maybe almost ten years - I can't remember for sure.  These E-Panels were created as a way to minimize the footprint of an inverter installation as well as the cost.  I don't always use E-Panels because the wiring space can get tight, but they certainly have their place and they are the only game in town if you want to make a Samlex EVO4024 installation safe and sharp looking.

This series of photos is probably a better illustration of how the E-Panel consolidates the AC and DC wiring as well as the associated breakers.  Note the big red breaker guard for the main DC cables on the left side of the E-Panel.

My experience with the Samlex EVO4024 was great.  The unit has a very nice relay that allows it to trigger the EcoGen generator to fire up automatically without the addition of any other electronics  Another plus for Samlex is the comparatively low cost of the system control panel.  The cost of inverter control panels has become a major hang-up of mine.  Some control panels cost more than $400!  That's a chunk of change for something that really resembles a beefed up thermostat.  Anyway, the controller for the EVO4024 costs less than $200.  It's probably the cheapest controller out there.  Finally, and most importantly, the technical support from Samlex was the best I have had from any inverter manufacturer.  By "best" I mean that there was no time wasted on hold and the support staff gave me the impression of being upper-tier right off the bat.  The technician who I spoke with was knowledgeable, polite and I got my questions answered while I was in the field.  I called multiple times and there was no deviation from this stellar service.