SANTIAGO, Chile — Jacquelin Marin has no running hot water at home. For a while, she had no real home at all. But soon she'll have both, with the sun heating water for her showers.

Marin and her neighbors are part of a pilot program to install solar water heaters in the houses of low-income families. For Chile — a country with stark economic inequality and few fossil fuels — it's a way to help the poor while also reducing greenhouse gas emissions.

Chile's drastically different climate zones mean it's hard to devise any nationwide energy solution. For now the program will begin in three disparate locations: 125 houses in the capital Santiago; 68 houses in Curanilahue, a rainy former coal-mining town 370 miles to the south; and 115 houses in Combarbala, 330 miles north in shrubby desert.

“I never had a water heater before, a husband who could install one, nor the money to fuel it,” said 39-year-old Marin.

In 2002, Marin joined a land takeover on the edge of a shantytown called Vista Hermosa, located in the poor western periphery of Santiago. Riot police, water cannon tanks and tear gas were not enough to dissuade the determined squatters. They stayed, constructing their homes with whatever materials they could purchase or find.

Marin and her neighbors from the shantytown went on to create a housing committee to change their flimsy abodes into real houses. They saved up, organized the neighborhood, staged protests and badgered authorities, until finally 125 families were awarded subsidies from the Chilean housing ministry to start a new housing project.

“Only 20 of the applicants were men,” said Leonardo Dujovne from the Housing Ministry. “All the rest were women.”

It was a long struggle and Marin, president of the housing committee Juntas Podemos (We Women Can), admits to fits of depression along the way, especially when they had to move their shacks down the road so construction could begin.

The squatters endured a prolonged lack of water and electricity at the new site, the cold of winter and rain leaking through tin roofs and flooding the neighborhood.

Some abandoned the project, moving back to swell the households of relatives as poor as themselves. Allegados, “added” relatives under the same roof, is a technical term in the overcrowded slums of Chile. Others, like Jacquelin, her husband and two children, stuck it out.

Today, Marin earns the minimum monthly wage of about $300 as the key keeper at the construction site of the 125 new homes that will go to as many families from Vista Hermosa. Her job is to ensure that fixtures and other finishes on the new homes stay put until she and her neighbors move in next April. “It’s like getting a brand new car,” she said, “and this one is a Mercedes!”

The basic unit has two stories, two bedrooms, and a floor space of just over 500 square feet. But it can be enlarged to three stories, up to four bedrooms and more than 750 square feet. Interior walls can be moved or removed, and floors added or subtracted.

Outer walls feature aerated concrete blocks with central cells, like cinder blocks, and millions of minute air bubbles in their walls for extra thermal insulation. The ceilings and bathroom walls are insulated with sheets of polystyrene foam covered by drywall.

To top off these cozy improvements, thermal-siphon solar water heaters crown the roofs.

The water heaters include a a flat solar collector and a holding tank for sanitary hot water, plus a kit to connect the water, pre-heated by the sun, to an auxiliary water heater. Fueled by conventional gas, the second heater can maintain or increase water temperature in the winter. The cost of each solar package with the auxiliary heater is $2,250.

The construction of an additional 297 houses nearby is planned to begin this year nearby. The per-house investment is close to $21,500.

For a family of four, using 10.5 gallons of water per day at a temperature of 115 degrees Fahrenheit, consumption of gas for heating water should drop by 62 percent. The new insulation standards should reduce energy demands for heat in winter by 45 percent and cooling demands in summer by 35 percent, said Minister of Energy Marcelo Tokman, while touring the site with then-President Michelle Bachelet.

Chile is a particularly poor country regarding fossil fuels. Almost three-quarters of its energy consumption during 2007 was based on fossil fuels: crude oil, natural gas and coal. The same year, the country had to import almost 100 percent of the crude oil and coal used, and most of its natural gas.

Petroleum products in Chile are as high as $4.35 per gallon of gasoline. Of course, with Chile’s minimum wage set at about $2 an hour, most laborers use public transport to get to work and, increasingly, bicycles to save on fare costs.

Solar water heaters are already popular in China, Israel and Spain. California recently approved rebates for switching from gas or electric water heaters to solar units, and beginning this year Hawaii will make solar water heaters mandatory on all new homes.

The first housing project in Chile with these energy savers will be christened "We Woman Can." Jacquelin Marin said she regrets that Bachelet won't be president when ribbons on her new neighborhood are cut, but she intends to invite Bachelet to the opening anyway. Maybe even to try her new hot shower.