JOHN: FOR YEARS, SOLAR POWER AT HOME WAS MOSTLY LIMITED TO PEOPLE WHO OWNED THEIR ROOFTOPS AND COULD AFFORD THE STEEP UPFRONT COSTS.

BUT THAT IS CHANGING.

A NEW GENERATION OF SMALL, AFFORDABLE SYSTEMS, OFTEN CALLED PLUG-IN SOLAR, ARE MAKING CLEAN ENERGY MORE ACCESSIBLE.

THE TECHNOLOGY IS ALREADY WIDESPREAD IN GERMANY AND THE MOVEMENT IS GAINING MOMENTUM IN THE UNITED STATES.

OUR REPORT IS FROM LAURA KLIVANS OF PBS MEMBER STATION KQED IN SAN FRANCISCO.

>> AGNES CHAN IS A RETIRED TEACHER IN BERKELEY, CALIFORNIA.

SHE WANTED TO INSTALL SOLAR PANELS ON HER HOME, BUT WAS LIMITED BY HER FIXED INCOME BUDGET.

>>I EVEN CONSULTED MY ROOFER, BUT THERE'S NO WAY THAT I CAN AFFORD THAT.

>> SO SHE FOUND A CHEAPER WORK AROUND AND IS ONE OF THE NEWEST ADOPTERS OF PLUG-IN SOLAR.

SHE HOPES TO REIN IN BILLS THAT RUN INTO THE HUNDREDS, EVEN WITH A THERMOSTAT SET TO 60.

>> IT'S A GREAT HOUSE I HAVE LIVED IN FOR OVER 35 YEARS, BUT THERE'S NO WAY TO INSULATE IT.

SO I'M SHIVERING IN MY OWN HOUSE.

>> INSTEAD OF TENS OF THOUSANDS OF DOLLARS FOR ROOFTOP SOLAR, THIS COST $400 AND TOOK LESS THAN AN HOUR TO INSTALL.

>> THIS WILL SHOW ME HOW MUCH THE PANEL IS GENERATING.

>> RATHER THAN TAKING A DECADE OR SO TO PAY IT BACK, IT WILL LIKELY TAKE HER TWO TO THREE YEARS.

>> WE ARE SYSTEMATICALLY REMOVING THE BARRIERS.

EPORTER: THIS NONPROFIT BRINGS PLUG-IN SOLAR'S TO RENTALS, PEOPLE IN MULTIFAMILY HOUSING, AND OTHER AMERICANS SHUT OUT OF ROOFTOP SYSTEMS.

>> THESE THINGS ARE MODULAR, THEY ARE TINY, YOU CAN PUT THEM ABOUT ANYWHERE.

YOU CAN ADD AS TIME GOES ON.

IT IS A LESSON BIG UPFRONT INVESTMENT AT ONCE.

EPORTER: FROM PLUG-IN CARPORTS TO BALCONIES, ENTREPRENEURS ARE INVESTING IN THIS EMERGING MARKET.

>> NOW THAT YOU'VE SEEN THE POSSIBILITIES FOR INSTALLATIONS - - REPORTER: BUT THERE'S A MAJOR HURDLE TO WIDESPREAD ADOPTION.

IN MOST OF THE U.S., IT IS NOT LEGAL TO JUST SET UP THE SYSTEMS AND PLUG THEM IN AS ENVISIONED.

>> THE NEXT TOPIC ON THE AGENDA, SO CALLED PLUG-IN SOLAR.

REPORTER: AT A RECENT ONLINE FORUM HOSTED BY CALIFORNIA'S UTILITY REGULATORS, IAN HOFFMAN WHO WORKS FOR PG&E SAID CUSTOMERS MUST COMPLY WITH REGULATIONS AND PAY FEES AS IF THEY WERE SETTING UP A ROOFTOP YSTEM.

UTILITIES ASSAY THAT HELPS THEM MANAGE ENERGY SUPPLY AND DEMAND BUT PLUG-IN SOLAR ADVOCATES SAY THEIR SYSTEMS SHOULD HAVE A SIMPLER REGISTRATION PROCESS.

>> THE WORLD HEADQUARTERS OF BROOKS ENGINEERING.

REPORTER:REPORTER: WE ASK AN INDEPENDENT EXPERT TO WEIGH IN.

BILL BROOKS IS AN ELECTRICAL ENGINEER WHO SPECIALIZED IN SOLAR FOR 37 YEARS.

HE HELPS WRITE CALIFORNIA'S CODE THAT GOVERNS HOW SELECTOR NEXT TO THE GRID.

>> THERE'S 78 SOLAR PANELS.

I CALLED HIM A SOLAR GUARD.

REPORTER: HE SAYS THERE ARE ISKS.

>>>> IF THE PRODUCT DID NOT HAVE PROPER CERTIFICATIONS, THERE WOULD BE THE POSSIBILITY THAT SOMEBODY COULD ENERGIZE A DOWNED POWER LINE THAT COULD INJURE A LINEMAN.

REPORTER: BUT BROOKS SAYS THE BARRIERS CAN BE OVERCOME BY UPDATING EXISTING TOOLS.

>> THIS IS A MICRO-INVERTER AND THINGS LIKE PLUG-IN SOLAR.

IT HAS A CERTIFICATION.

AND WE HAVE THE NATIONAL ELECTRICAL CODE.

REPORTER: WHEN THESE SAFEGUARDS ARE IN PLACE, BROOKS DOES NOT SEE THE NEED FOR A LENGTHY OR COSTLY REGISTRATION.

AND HE SAYS INDEPENDENT ORGANIZATIONS ARE WORKING ON A SAFETY STANDARD FOR THE TECHNOLOGY.

BUT PLUG-IN SOLAR COMPANIES AND THEIR CUSTOMERS ARE NOT WAITING FOR REGULATORS.

BAY AREA RESIDENT JOE TENENBAUM CONSIDERED ROOFTOP SOLAR WHEN HE HAD RISING ELECTRICITY BILLS.

>> A GOOD AMOUNT OF SUNSHINE FROM EARLY ON.

REPORTER: BUT IT WOULD REQUIRE REPLACING THE ROOF, TOO.

AND COSTS QUICKLY BALLOONED.

>> AND WE DON'T OWN THIS HOUSE.

THIS IS MY PARENTS' HOME.

MY WIFE AND KIDS AND I MOVED IN WHEN MY MOM GOT SICK.

IT IS NOT FEASIBLE FOR THEM TO MAKE IT 100 THOUSAND DOLLAR INVESTMENT IN A ROOFTOP SYSTEM AND IT IS NOT EITHER FOR US.

REPORTER: TENENBAUM LIKES THE IDEA THAT THEY WOULD BE ABLE TO TAKE THEIR PANEL WITH THEM IF THEY MOVED.

FOR $1600, HE BOUGHT AN 800 WATT DIY KIT FOR -- AND HE LIKED HOW THEY BUILT SAFETY MEASURES INTO THEIR TECHNOLOGY.

THE COMPANY ALSO ADVISES CUSTOMERS TO REGISTER THEIR SYSTEMS.

THE PANELS WON'T POWER THE WHOLE HOUSE BUT WILL KEEP TENENBAUM'S REFRIGERATOR HUMMING AND SMALL APPLIANCES CHARGED.

HE EXPECTS TO SAVE 5% TO 10% ON HIS MONTHLY UTILITY BILL.

CRAFT FROM CO-FOUNDER AND BROTHERS MICHAEL AND STEPHEN SAY DEMAND FOR PLUG-IN SOLAR IS GROWING.

>> BASICALLY HERE IN CALIFORNIA, PEOPLE ARE TELLING US ABOUT THE TIME OF USE RATES THAT DOUBLE AS THEY COME HOME AND USE HOWARD.

THE SECOND -- USE POWER.

THE SECOND MOTIVATION IS THE GREEN REVOLUTION.

REPORTER: LEGISLATORS ACROSS THE COUNTRY ARE TAKING NOTE.

>> WE KNOW THEY ARE SAFE BECAUSE THEY'VE BEEN DOING THIS FOR FOUR YEARS NOW AND IT HAS WORKED OUT WELL.

REPORTER: EARLIER THIS YEAR, YOU TALK PAST THE FIRST LEGISLATION NATIONWIDE TO ALLOW PLUG-IN SOLAR WITH NO REGISTRATION WHEN CERTAIN SAFETY STANDARDS AND CODES ARE SET.

SIMILAR LEGISLATION IS IN THE WORKS AND SEVERAL OTHER STATES INCLUDING NEW YORK, NEW HAMPSHIRE, PENNSYLVANIA AND VERMONT.

>> MY PANEL IS PRODUCING 645 WATTS PER HOUR.

EPORTER: AS FOR AGNES CHAN IN CALIFORNIA, SHE IS HOPING TO STAY WARMER THIS WINTER.

>> I EXPECT TO BE COMFORTABLE INSTEAD OF SHIVERING IN MY OWN HOUSE, WEARING A DOWN JACKET AND A BLANKET TO WATCH TV.

REPORTER: EVEN IF EVERYONE IN THE U.S.

HAD THESE PANELS, PLUG-IN SOLAR COULD ONLY COVER A SLICE OF THE NATIONAL ENERGY DEMAND, BUT EXPERTS SAY EVERY BIT OF RENEWABLE ENERGY COMES.

>> BIG MOMENT HERE.

I'M VERY EXCITED ABOUT THIS NEW SYSTEM.

JUST ON BOXING IT FELT LIKE OPENING UP A GIFT.

>> WE HAVE SOLAR.

>> THAT'S ALL THERE IS TO IT.

REPORTER: FOR PBS NEWS WEEK AND, I'M LAURA CLIVANS IN NORTHERN CALIFORNIA.