I N T R O D U C T I O N PEACE AND WAR WEALTH AND POVERTY PROGRESS AND SETBACKS HISTORY HAS BROUGHT HUGE SWINGS IN THE HUMAN CONDITION AND WITH EVERY CHOICE PEOPLE MAKE THERE IS THE POTENTIAL TO MOVE FORWARD OR STEP BACKWARD AT THE CORE OF THIS CONTINUAL STRUGGLE HAS BEEN THE QUEST FOR ENERGY ENERGY GAVE HUMANS POWER AND MOTIVATED THEM TO DO GREAT THINGS WITH BOTH POSITIVE AND NEGATIVE EFFECTS WITHOUT ENERGY PEOPLE WOULD NOT BE ABLE TO DRIVE CARS OPERATE COMPUTERS OR POWER FACTORIES WARS ARE FOUGHT TRYING TO DOMINATE SOURCES OF ENERGY FORTUNES ARE MADE AND LOST DEPENDING ON HOW THAT ENERGY IS MANAGED THE LAWS OF PHYSICS STATE THAT ENERGY CANNOT BE CREATED OR DESTROYED THAT IS TRUE BUT ENERGY CAN BE HARNESSED AND DIRECTED IT CAN BE WASTED OR IT CAN BE COAXED INTO EFFICIENCY CIVILIZATIONS AND TECHNOLOGIES HAVE LEAPED FORWARD AND SOMETIMES BACKWARD AS HUMANS HAVE TAPPED INTO EARTH’S SOURCES OF ENERGY Solar technology allows humans to tap into the sun’s energy 4
The sun is our planet’s oldest largest and most reliable source of energy But even though people have used the sun’s power heat and light to keep warm for thousands of years modern solar energy is still not widespread The sun leaves its bright mark every where it seems except in the power we use for our daily needs That is changing as solar power systems are spread all over the world In some places it’s just a few solar panels on the roof of a home In others it’s thousands of mirrors lined up across a sunny desert generating electricity for thousands Fossil fuels are becoming scarcer more expensive and are caus ing more problems But the sun shines every day In the future the solar industry could shine too 5
CHAPTER ONE NOTHING NEW UNDER THE SUN THE SUN IS THE ULTIMATE SERVANT It doesn’t argue never takes a day off and even works for free Ancient peoples recognized that the sun just like a hard-working servant provided everything in their lives Its heat gave them warmth Food came from plants nourished by sunshine Grateful for its power and energy many cultures worshiped the sun viewing it as a deity Today people are less likely to worship the sun but it’s still the source of virtually all Earth’s energy Although 93 million miles 150 million km away this is one long-distance relationship that’s not going to fizzle out Ancient Egyptians thought of the sun as a great boat that carried the gods across the sky 6
People can save money and make use of passive solar energy for drying clothes or heating buildings Each second the sun burns up millions of tons of its own mass turning it into light and heat Only a tiny fraction of that energy ever reaches Earth Even so in less than an hour and a half the sun delivers enough energy to power the world’s people for an entire year It’s estimated that just 20 days of sunlight provide as much energy as is stored in all the world’s reserves of fossil fuels Of course people can capture only a very small portion of all that solar energy but fortunately that’s all they need At its most basic level solar energy is easy to use All it requires is the sun and something that absorbs heat Drying clothes outside uses solar energy So does frying an egg on the sidewalk on a hot summer day Make sure it’s a clean sidewalk first This passive solar energy is simply heat and light that is collected from the sun It does not involve converting the sun’s energy into another form such as electricity as active solar technology does People have used passive solar energy for thousands of years In ancient Greece and Rome architects and engineers designed towns and cities to have as many homes as possible facing south where they could get the most sun in the winter As cities grew more buildings sometimes blocked the sun from reaching existing structures In the sixth century A D the Romans passed a law making it illegal to construct a building 7
