How Puerto Rico measured power restoration after Hurricane Maria

The October snapshot used load as a proxy

The Department of Energy says the local utility reported almost all Puerto Rico customers without power on 20 September 2017, apart from facilities running on generators. The 19 October situation report put load at 579 MW, about 21.6% of normal peak. It used load as a proxy for customer outages because a more accurate customer count was unavailable. Source 1 Source 2

A January report showed the two measures separately

The 3 January report gave 69.4% of normal peak load restored and 57% of customers with power. The observation times differed by a day. The report also flagged a recent recalibration of average peak load, which matters when comparing the load series across the recovery. Source 3

By March, the customer share had overtaken the load share

The 7 March report showed 89.43% of customers with power and 88.3% of normal peak load restored. The 28 March report recorded 94.56% of customers and 90.1% of peak load. The share of customers had moved more than the peak-load percentage between those snapshots. Source 4 Source 5

Partial municipal restoration left customers without service

By the 4 April report, all 78 municipalities had at least partial service. The utility still estimated 61,914 customers without power on 3 April, with 1,411,086 restored. Restored load was 89.2% of the normal peak that day, down from the 28 March snapshot while the customer share continued to rise. Source 5 Source 6

How Puerto Rico measured power restoration after Hurricane Maria

Normal peak load restored

Customers with power

The October snapshot used load as a proxy

A January report showed the two measures separately

By March, the customer share had overtaken the load share

Partial municipal restoration left customers without service

Sources