Solar Energy
Introduced| English |
|---|
| Solar/ˈsəʊlə/ |
| Active/ˈæktɪv/ |
| Passive/ˈpæsɪv/ |
| Photovoltaic/ˌfəʊtəʊvəʊlˈteɪɪk/ |
| intermittent/ˌɪntəˈmɪtənt/ |
Power from the sun
- The sun pours more energy on Earth in an hour than we use in a year.
- Solar 太阳能 power captures some of that free energy.
- It makes no smoke and no CO2 while running.
- There are two main ways to use it: active and passive.
Active solar
- Active 主动式 solar uses equipment to collect and move energy.
- Photovoltaic 光伏 (PV) panels turn sunlight straight into electricity.
- Solar water heaters use pumps to move sun-warmed water.
- These systems have parts, wiring, and sometimes pumps.
Solar photovoltaic (PV) panels make…
Photovoltaic cells turn sunlight straight into electricity, with no burning and no moving parts.
Passive solar
- Passive 被动式 solar uses smart design, with no equipment.
- South-facing windows let winter sun warm a room.
- Thick walls and floors store daytime heat and release it at night.
- Roof overhangs shade the windows in summer.
Active or passive solar?
Sort each example by whether it uses equipment (active) or just smart design (passive).
Passive solar design uses…
Passive solar uses clever design — windows, thick walls, overhangs — to catch and hold heat with no devices.
While running, solar power produces no CO2 and no air ____.
Solar power makes electricity with zero emissions while it runs — a major clean-energy advantage.
The catch
- Solar only works when the sun shines — it is intermittent 间歇性.
- Output drops at night and on cloudy days.
- Cloudy or high-latitude places get far less.
- To use solar at night, you need batteries to store it.
A drawback of solar power is that it makes no electricity at night.
Solar depends on sunlight, so output drops at night and on cloudy days — it is intermittent.
Select all advantages of solar power.
Solar is clean, renewable, and rooftop-ready — but it works far better in sunny places than cloudy or high-latitude ones.
Keep active and passive straight. Active = equipment (PV panels, pumps) that collects or converts solar energy, often into electricity. Passive = design (windows, thick walls, shade) that captures heat with no moving parts. If it has a panel, wire, or pump, it's active; if it's just the shape and materials of the building, it's passive.
One sunny house:
- On the roof, active PV panels feed electricity to the lights and fridge.
- Inside, big south-facing windows and a thick stone floor are passive — they soak up the sun's warmth all day and release it after dark, with no machine at all.
- Both cut the fuel bill; only one has moving parts.
Solar power captures the sun's energy with zero emissions while running. Active solar uses equipment — photovoltaic panels for electricity, pumps for hot water. Passive solar uses building design — windows, thick walls, overhangs — with no moving parts. Its main drawback is being intermittent: no power at night or under heavy cloud.