The Myth of Whole House Battery Backup

The Myth of Whole House Battery Backup

Will batteries keep your AC cranking and electric vehicle charged up during an extended blackout? Probably not.

We like to believe the myth of whole house battery backup or the notion that our 21st century lifestyle will continue unabated despite fire hell or high water. The reality is different: Typical battery backup systems work best when they are designed to ration battery capacity and minimize the use of major appliances. These systems must also be integrated with rooftop solar so that the battery can be recharged as soon as the sun comes up.

There are two fundamental engineering limits that make it impractical to run a whole house on battery power alone. First, the energy capacity of typical lithium-ion battery systems is insufficient to power an entire house through a nighttime blackout. Second, battery backup inverters are not powerful enough to start and run many large appliances. Adding multiple batteries and inverters can overcome these engineering limits – but at a very high cost.

Nevertheless, a well-designed solar and whole house battery backup system can provide limited power almost indefinitely. To learn more about the reality of backup power in the event of a blackout or Public Safety Power Shutoff, please listen to this week’s Energy Show.

New Battery Storage Systems

New Battery Storage Systems

The 16th annual Solar Power International show was held this October in Salt Lake City. It’s been quite a growth story since the first show in 2004 in San Francisco, which was held in what is now just a lobby of a downtown skyscraper. Not only has the industry grown, but the range of equipment being exhibited has increased dramatically.

Recently, the biggest change has been towards new battery storage systems. Entire sections of the exhibit halls were dedicated towards energy storage in a periodic table hodge podge of elements: hydrogen, lithium, vanadium, cobalt, nickel, zinc, lead, etc. — everything except my favorite element, Solarium.

To me the real action was with the heart and brains of these battery storage systems: inverters. Pioneers of turnkey residential battery storage prodcuts — Outback, SMA, SolarEdge, Enphase — were joined by just about every company that manufacturers inverters or batteries, including Fronius, Delta, LG Electronics, Q-Cells, Panasonic, Sonnen, Generac and others.

But a nice brochure and fancy booth demos don’t always translate into products that customers can actually install today. Please listen up to this week’s Energy Show as we review the most notable battery storage systems spotted on the floor of Solar Power International 2019.

Reducing Peak Demand Charges

Reducing Peak Demand Charges

Unless you have rooftop solar, you’re probably incredibly unhappy about rising electric bills. This misery is even worse for commercial customers since — in addition to energy charges (billed on a kilowatt-hour basis) — they also pay for peak demand charges (billed on the maximum kilowatt demand each month).

For example, let’s say your business uses industrial equipment and a variety of office equipment. Your company uses 50,000 kwh of energy per month; at a rate of $0.15/kwh, your electric bill is $7,500 per month. In addition, your peak demand may be 300 kilowatts in a typical month; at a peak demand rate of $20 per kilowatt, you also pay $6,000 in demand charges every month.

As a conscientious and generous employer, you decide to install 20 EV chargers in your parking lot so your employees can charge up their cars while at work. Each employee may charge up their car with about 10 kwh per day — or $1.50 worth of electricity each, or $600 for all employees each month. A nice employee perk, and not too expensive. However, since 20 employees plug in their cars at about the same time every morning, and each charger draws about 5kw, your extra electricity peak demand will be 100 kw, or an extra $2,000 per month. Ouch!

So for many commercial customers, peak demand charges are a bigger cost than energy charges. Ordinary rooftop solar systems may not have a big impact on demand charges. However, batteries or special control systems in conjunction with rooftop solar can significantly reduce these demand charges.

To learn how your company can reduce peak demand charges, listen to this week’s Energy Show as we speak with John Powers with Extensible Energy. Extensible Energy has software that helps commercial solar buildings to use electricity intelligently and reduce peak demand charges.

Living With Public Safety Power Shutoffs

Living With Public Safety Power Shutoffs

PG&E, our local utility in Silicon Valley, caused a number of wildfires — including the recent Camp fire that destroyed the town of Paradise, killed 86 people and destroyed over 13,000 homes.The primary reason for this and other similar fires is that PG&E skimped on power line maintenance while enjoying record profits. Now they are bankrupt (again), and are scrambling to deal with the upcoming wild fire season.

Public Safety Power Shutoffs may happen far from fire danger areas. And these shutoffs could last for 48 hours or longer. So anyone relying on electricity for the necessities of life must prepare for an extended outage. Unfortunately, their recommendations ignore the cleanest, cheapest and safest backup power solution – solar and battery storage. Instead, PG&E recommends gas generators and stockpiling several days of fuel. Dumb idea to store all this extra fuel in fire-prone areas. Not to mention the challenges of connecting, starting and operating a gas generator safely.

Here is the letter that PG&E sent to my home:

Given the growing threat of extreme weather, we want all of our customers to be prepared for power outages. If elevated weather conditions, including potential fire risk, threaten a portion of the electric system serving your community, it will be necessary for us to turn off electricity in the interest of public safety. This is called a Public Safety Power Shutoff. We know how much our customers rely on electric service and want to work together to help you prepare for power outages.

A Public Safety Power Shutoff could impact any of our more than 5 million electric customers, including your home or business. Because elevated weather conditions can last several hours or days, we suggest preparing for outages that could last longer than 48 hours. Electric backup generators can keep the lights on, help appliances stay running, preserve perishable foods, and power essential equipment and electronics during a power outage.

Generators can also pose safety hazards, so it is important to understand how to safely operate your generator before an emergency occurs. This means doing regular safety checks and being sure you have enough fuel to last a few days.

As you can see from their letter above, PG&E recommends a gas generator for backup power (remember, the “G” in their name stands for “GAS”). No mention at all about using a cleaner, cheaper, quieter and safer battery backup system. Simple reason: they don’t want you to install solar or batteries since that reduces their revenue and profits. And if you buy an automatic natural gas generator they’ll make even more money selling you natural gas.

So Listen up to this week’s Energy Show as we discuss your options for dealing with these Public Safety Power Shutoffs — as well as considerations for selecting the best battery backup system to protect you and your family during these outages.

Public Safety Power Shutoff Programs

Public Safety Power Shutoff Programs

California utility companies recently announced their Public Safety Power Shutoff programs across the state. Bloomberg News said “California May Go Dark This Summer and Most People Aren’t Ready.” California’s Governor Gavin Newsom was quoted as saying “I’m worried. We are all worried about it for the elderly. We are worried about it because we can see people’s power turned off for not just for a day or two but potentially for a week.”

These public safety power shutoff events are already happening around the state. Utilities turn off the power if there is the possibility of danger imposed by things such as high winds or wildfire, dry vegetation, low humidity, observations of dangerous conditions by field personnel and red flag warnings from the National Weather Service. The Paradise fire in 2018 was started when PG&E decided NOT to shut power off in a fire prone area. Now all utilities are erring on the side of caution, shutting off power when there may only be a remote chance of a fire – certainly better than burning down a town.

Unfortunately, looking back over the past fifty years, the reliability of our power grid is not getting better. The weather is getting hotter, there is more housing in forested areas, we need electricity more than ever, and some utilities have been skimping on maintenance to maximize their profits. Electricity has become the most important fuel for our society. So when the lights go out, our 21st century lifestyle reverts to the19th century.

To learn more about these Public Safety Power Shutoff programs, what the utility companies suggest (buy a gas generator!), plus better solutions (hint: solar with battery backup), Listen Up to this week’s Energy Show.

Avoiding Battery Storage Installation Mistakes

Avoiding Battery Storage Installation Mistakes

Upcoming electric rate changes mean that almost every home and business will eventually benefit from a battery connected to their solar system. These combined systems provide tangible economic benefits: time shifting energy use, energy arbitrage, preserving the benefits of net metering and demand charge reduction.

In a nutshell, battery storage systems help preserve the benefits of net metering. But because of the grid’s unreliability — coupled with upcoming Public Service Power Shutoffs in California — the vast majority of our residential customers are installing battery storage systems for backup power.

As our company got back into the energy storage business with lithium ion batteries, we did extensive research into battery systems and their compatible inverters, into manufacturers, into software and operating modes, and into the interconnection and incentive process. After almost two years of selling and installing battery storage systems we’ve gained a lot of wisdom — and made some mistakes along the way. To help our fellow contractors and our future customers, here are ten of our most systemic and painful battery storage installation mistakes:

1. Misunderstanding customer desires 
2. Incomplete product offerings 
3. Underestimating support and maintenance costs 
4. Adding batteries to existing systems  
5. If the CTs don’t fit, you’re in deep sh-t  
6. Complicated backup panel wiring  
7. Buggy software and firmware 
8. Interconnection problems 
9. Incentive delays 
10. Battery warranty claims 

For more insights into avoiding battery storage installation mistakes, please Listen Up to this week’s Energy Show.