共用题干Better Solar Energy Systems:More Heat More Li

共用题干

Better Solar Energy Systems:More Heat,More Light

Solar photovoltaic（光电的）thermal energy systems , or PVTs , generate both heat and electricity , but
_________ (51)now they haven’t been very good at the heat-generating part compared to a stand-alone
solar thermal collector. That ’ s because they operate at low temperatures to cool crystalline silicon（晶体硅）
solar cells, _______(52)lets the silicon generate more electricity but isn’t a very efficient way to gather
heat.
That’s a problem of economics.Good solar hot-water systems can harvest much more energy than a
solar一electric system at a substantially lower _________(53).And it’s also a space problem:photovoltaic
cells can
_________(54)up all the space on the roof,leaving little room for thermal applications.
In a pair of studies,Joshua Pearce,an associate professor of materials science and engineering,has de-
vised a_________(55)in the form of a better PVT made with a different kind of silicon.
Most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous
（非晶形的）silicon , commonly known
________( 56 ) thin-film silicon. They don ’ t create as much elec-
tricity,but they are lighter,flexible,and cheaper. And,because they________(57)much less silicon,they
have a greener footprint._________(58),thin-film silicon solar cells are vulnerable to some bad一news
physics in the form of the Staebler-Wronski effect.
"That means that their efficiency drops when you_________(59)them to light一pretty much the worst
possible effect for a solar cell,"Pearce explains,which is one of the__________(60)thin-film solar panels
make up only a small fraction of the market.
However,Pearce and his team found a_______(61)to engineer around the Staebler-Wronski effect by
incorporating thin-film silicon in a new________(62)of PVT. You don’t have to cool down thin-film sili-
con to make it work.In fact,Pearce’s group discovered that by heating it to solar-thermal operating tempera-
tures,near the boiling_________(63)of water,they could make thicker cells that largely_________(64)
the Staebler-Wronski effect.When they applied the thin-film silicon directly to a solar thermal energy collector,
they also found that by baking the cell once a day,they_________(65)the solar cell’s electrical efficiency
by over 10 percent.

_________(61) A:way B:part C:result D:subject