When the Grid Fails

Stay safe and reduce economic loss during grid outages, power shutoffs and curtailment

With power outages caused by extreme weather and centralized grid failures on the rise, distributed energy resources in the form of pv and energy storage help mitigate the health risks, economic risks, and losses that occur during these catastrophic events.

The frequency and length of power failures are at their highest levels since reliability tracking began in 2013 – with US customers on average experiencing more than eight hours of outages in 2020. The North American Electric Reliability Corporation made an assessment for the summer of 2022, warning that the Midwest, Arkansas, Mississippi and Louisiana are at “high” risk of its energy reserves falling short of its normal energy needs. Texas and the western U.S., according to the report, are at “elevated risk” of seeing grid shortages.

Power outages from severe weather have doubled over the past two decades, crippling broad segments of the nation’s antiquated electrical grid. The blackouts are expensive and involve economic losses outside of the immediate reach of those affected. In addition, blackouts are harmful and even deadly for the elderly, disabled, and other vulnerable communities. The Campfire disaster that devastated California killed over 85 people and damaged over 18,000 structures along with the Texas freeze from a few years ago are just two examples of how vulnerable our electric grid really is.

Why are distributed energy resources so important now?

The costs involved in repairing, maintaining, and upgrading the utilities’ decades-old transmission lines and equipment are skyrocketing. Customers are paying more for electricity while experiencing more frequent and longer outages. Given that we know the grid is unreliable and expensive to maintain we need to look towards producing and storing energy that can be used onsite.

Distributed energy resources are the most reliable way to eliminate the risks that come from climate related and other disasters that affect the distribution of centralized energy resources. Energy storage plays a critical role in distributed systems which are typically powered by solar pv. Simply put, without energy storage, the systems will not work if the sun is not shining, or the wind is not blowing.

While this is true, this is old rhetoric as energy storage reverses this narrative that solar, wind and other renewables are unreliable due to intermittency. With energy storage, safely deployed, we have access to power 24/7.

Deploying safe energy storage systems is as important as deploying distributed energy storage systems.

Distributed energy storage systems, while critical in our fight against climate change and efforts towards grid resiliency, must be certified and fire-safety tested to the highest levels to ensure that the systems we deploy meet the needs of our communities.

We are constantly hearing reports about fires, explosions and other thermal related events which can be eliminated by using the highest quality manufacturing processes paired with chemistry that does not inherently risk thermal runaway.

Cobalt is a common element found in batteries that enter thermal runaway. The New Jersey Department of Health and Senior Services claims cobalt “is flammable and may ignite spontaneously.” In addition, there are numerous human rights issues associated with the extraction and trade in cobalt.

There are various types of battery chemistries available (NMC, LFP, NCA and LCO), but not all chemistries, form factors, and manufacturing processes provide the same results with an equal level of safety. For this reason, the UL 9540A fire-safety test method was developed to help manufacturers have a means of proving the safety of their ESS. UL 9540A testing shows that a well manufactured energy storage system using LFP (Lithium Iron Phosphate) battery chemistry eliminates the risk of thermal runaway.

These tests allow a manufacturer to develop a reference library and see how their battery will perform under normal to extreme conditions. At the cell level, battery level, and integrated unit level the equipment being tested is put into safe, controlled environments where there are “witness boards” that collect shrapnel and other materials if explosions occur. Thermocouples are built-in throughout the unit, both internally and externally, to force the materials into thermal runaway.

A well-built battery, using safe Lithium Ferro Phosphate (LFP), will not go into thermal runaway involving fire, nor explode even under extreme operating conditions.

The obvious safety risks, potential human injury, and economic losses that can occur with a poorly made or incorrectly installed energy storage system make this fire-safety test report crucial in the permitting process for Authorities Having Jurisdiction, fire departments, codes officials and other permitting agencies.

What to look for when choosing an energy storage system.

Since safety is one of the main concerns, be sure to choose equipment that has been certified to UL 9540 and fire-safety tested using the UL 9540A testing methods described above. Other factors to consider are:

• Battery chemistry: What is the actual battery made of? As we mentioned above, LFP chemistry in a well manufactured battery cannot go into thermal runaway involving fire or explosion.
• Cycle life: How many times can the batteries be charged and discharged? A good battery will allow for 10,000 cycles or more.
• Warranty: How long will the manufacturer guarantee the system from the date of purchase? A quality system should come with a 10-year warranty.
• Operating temperature range: Choose a system that will perform in a variety of conditions as places that have never seen frost are experiencing freezing weather and normal summer temperatures are rising.
• Charge and discharge rate: this is the rate that the battery can deliver power and be re charged. A battery can overheat if discharged too rapidly so it is important to have a discharge rate that can handle the potential rate of power usage.

Ideally, consider the ultimate purpose of deploying an energy storage system, which is reliability, versatility, and safety.