CFLs Improved Electric Supply
CFLs Improved Electric Supply
When the CEMIG utility in Brazil gave away CFLs in a very
poor region, not much energy was saved. However, the CFL program helped
stabilize supply voltage and allowed poor customers to enjoy increased
quality lighting services and run household appliances without forcing
the utility to invest in new generation capacity.
In 1995Đ96, CEMIG (Mi–as Gera’s State Energy Company), Brazil's second
largest distribution electric utility, tested a direct-install, free CFL
program in which 89000 9W CFLs were given away to low-income customers.
The objective was to ease the burden on the transmission and distribution
system, which experienced frequent brownouts. CEMIG ran their give-away
program in a very poor region, Vale de Jequitinhonha. The area faced acute
generation and distribution capacity shortages, and voltage drops were
commonplace during peak hours. This meant that previously installed incandescent
lamps had given much less light than their rated luminous flux and that
several other appliances could not even function properly. It was hoped
that the massive lamp replacement would help the utility deliver proper
voltage and current to their customers, thus helping them reach an acceptable
lighting service level (and, as a side effect, run appliances). The utility
visited households with an energy consumption below 50kWh/month and offered
them installation of one or two 9W CFLs for free. A total of 89000 lamps
were given away to 52000 households. CEMIG ran a proper ex-ante, ex-post
evaluation. A detailed household survey and investigation into appliance
ownership preceded the give-away. Detailed aggregate metering was also
conducted on the utility system to determine how much electricity and
load savings could be attributed to the program. The utility estimates
that the total cost per lamp, including installation, was US$8 per CFL.
SMALL REDUCTIONS, LARGE BENEFITS
The results of CEMIG's program are confusing at a first glance. CEMIG measured a total peak-load reduction of 1845 kW, which is little for a program that deployed 89000 lamps to 52000 households with only few lighting sockets (virtually a 100% participation rate). CEMIG also measured the total annual electricity savings to be about 850 MWh, which yields an annual savings of ~9.5 kWh per lamp. However, CEMIG was in fact dealing with a situation of repressed demand, which was freed when the peak load constraints had been overcome. Part of the potential CFL savings were thus offset by both longer burning hours and by the fact that many appliances that previously had not been regularly operable due to voltage fluctuations could now be operated as the customer wished.
Nils Borg