Is a battery backup system right for you?

If you live anywhere in southern Vermont, it is likely that you have experienced a power outage in the past few years. In fact, due to the heavy snow that fell overnight on November 26, 2018, many thousands of our local utility’s customers were without power for an extended period of time.

If you were one of those people, you may be wondering if a clean, renewable energy and battery backup system is right for you. Here are a few things to consider:

  1. If you experience frequent extended power losses, a backup system to energize your critical loads would be a good alternative to waiting in the dark for power to be restored, or listening to a noisy generator for several hours or days;
  2. If you experience infrequent power outages, but still want the security that comes with having heat and lights, a battery backup system might be your answer; or
  3. If you need electricity for critical loads that should not be without power, a battery  system with a backup generator may be right for you.

A typical battery backup system includes the following components:

  • Battery bank – battery chemistry may be lithium, lead-acid, or other technology that stores power for later use;
  • Inverter – this converts the direct current (DC) electricity in the battery bank into alternating current (AC) that your house loads use. It may or may not include a means of charging the battery bank;
  • Solar array – if you want to generate electricity for use by your house loads or to store in your battery bank, an array comprised of solar panels would turn the sun’s energy into electricity. The solar array may require a charge controller between the solar panels and battery bank.

Net Zero Renewable Resources has extensive experience in designing and installing battery backup and off-grid systems to get you through those days when the electrical grid is down (in fact, we live off-the-grid). There are many different options to meet your needs and budget, and we are happy to talk to you about how we can help you get through the next power outage. Please call us for more information at 802-875-3654, email us at info(at), or complete our contact form.

We look forward to hearing from you!

Living Large Off-Grid

We recently completed installing a large off-grid system for a customer in Vermont. This was a complex and significant project for us, and we wanted to get all the details right and make a good impression on our customers. We started discussing the project with the local electric utility about six months before we finalized the design, which we completed in early Spring.

To meet a daily demand of around 60 kilowatt-hours, we selected Schneider Electric (SE) inverters and charge controllers, Blue Planet Energy Blue Ion batteries, and trackers manufactured by AllEarth Renewables for this system. Each of the two 24-module trackers are wired with 12-module strings, with the output from each string connected to a fused safety switch, then to a SE Power Distribution Panel (PDP). Ten 16 kWh battery cabinets are connected to a battery bus, then wired to the PDP. The output from three SE XW+6848 inverters is connected to the home to power the loads. An auto-start generator can be used to charge the battery bank and power loads when necessary.

System monitoring is accomplished using a eGauge for the battery bank, which allows tracking numerous parameters, and a SE Combox allows remote viewing of solar production and loads.

This project is the largest installed by Net Zero Renewable Resources, and the largest BPE battery bank installed to date. The system has proven to be a robust and reliable power supply to the home, and we anticipate many years of clean energy production for our customer.

If you are interested in this project, or would like to inquire about a similar system for your home, please contact us. We look forward to hearing from you!


Happy customers

One of the best things about installing solar is the happy customers. I love the look of joy on their faces when they start making their own power!


Face the Wind

We were recently called to look at a wind turbine that was not working properly. The tail was at a right angle to the blades, and it was not making power, since the turbine did not face the wind. The site was great for a turbine, at the top of a hill, with plenty of open area in all directions.

Wind turbine not working, crooked tower, loose cables

Turned out that the mast was not plumb, and as a result, the weight of the turbine caused the blades to always point down, no matter which way the wind was blowing. We got the site and started pulling on the guy wires, and once the tower was plumb, the tail straightened out, and the turbine started to make power.

It took us a bit, but we got the mast pretty straight, and the cables tightened. All of the cable clamps were loose, probably as a result of constant movement of the tower.


Recommendation: check your cables and clamps every six months!

Wind turbine fixed!
Wind turbine working properly

PV Production – Part 2

I have been looking at the production of three different PV systems – tracker, roof, and pole mounts. A roof mount is the least expensive option because the infrastructure for the mount is already in place. Pole-mounts are usually the next least-expensive option, since the mounting equipment is fairly simple to manufacture and install. The trackers are the most expensive, due to the complexity of the tracking system. However, these units produce significantly more power then either of the other two types of systems.

tracker1The graph shows the production of these types of systems since June 2014, normalized to account for differences in array size. As you can see, the trackers have produced around 44% more than a roof system, and 26% more than a pole mount. Winter production of the tracker is where these units out-perform the others.

If you would like more information about trackers, or any other type of renewable energy system, please contact us. We look forward to helping you!