After its water system lost power during widespread power outages in mid-February, Abilene, Texas, is considering setting up a microgrid.
During Winter Storm Uri, the Electric Reliability Council of Texas, which manages most of the state’s electric grid, ordered blackouts that affected about 4.5 million people over five days and led to at least 210 deaths, according to state officials.
Abilene wasn’t able to produce drinkable water and was unable to obtain water from its suppliers, according to a memo city staff wrote for a July 27 city council budget meeting.
As a result, Abilene’s customers, including wholesale water providers served by the city, lost all water service for 27 hours and were under a mandatory boil water notice for six days, said the memo.
Abilene, a city of about 125,000 people, has three treatment facilities and three main water supply sources. The outages at the treatment plants ranged from 18 hours to 40 hours.
Water systems across Texas hit with outages
Abilene wasn’t alone in losing power at critical water facilities during the winter storm.
More than a quarter of Texans were under a boil water notice, according to the memo. About 2,230 public water systems in Texas issued boil water notices during the winter storm event, including 23 community water systems serving populations of at least 100,000, staff said.
After considering its options, city staff recommended adding backup diesel generators at the water treatment plants and creating a microgrid at one of them.
Microgrid saves $2M over diesel backup
The microgrid is expected to cost $2.2 million, providing $2 million in savings compared with adding diesel generators at the facility, according to the memo.
“There are several advantages with microgrid systems, in addition to the cost savings, namely higher reliability due to increased run time to offset the capital expenditure by the vendor,” staff said.
Backup diesel generators aren’t foolproof, according to the memo, which noted 20% of Houston’s backup generators didn’t work during the winter storm. Since the storm, Houston has also been considering setting up microgrids at critical facilities.
Some Texas water agencies are already using microgrids to bolster reliability. Enchanted Rock last year landed a contract to set up a 2.4-MW microgrid for the North Fort Bend Water Authority to ensure water deliveries during power outages.
Under a state law that took effect in June (SB 3), water utilities face tougher standards for operations during extreme weather.
Abilene hired Enprotec/Hibbs & Todd, an engineering firm, to study the options for increasing the power resilience at the water facilities.
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