Solar Thermal Flashcards
(25 cards)
What is solar thermal?
Using incident solar energy to generate useful thermal energy
What is passive solar?
Passive solar is using simple ideas without mechanical or electronic devices
What are the types passive solar?
Direct gain, indirect gain and isolated gains
What is the U-value of a material?
U-value is the thermal performance, lower the better
What is the daylight factor?
Ratio of internal light to external light
Name three advantages of passive solar
Simple designs, little to no maintenance, and reduced fossil fuel dependence
Name three disadvantages of solar thermal
Can be expensive if retrofitted to existing buildings, dependent on local climate and reduced efficiency
What do solar water heaters consist of?
Solar collection panels, pumping systems and storage tanks
What are the types of solar water heaters?
Unglazed, flat- plate water heater, flat-plate solar air heater and evacuated tube solar water heater
Name three advantages of solar water heaters
Zero emissions, high cost and low efficiency
What is a thermosyphon system?
This is a pumped storage system where water flows down tank where it is heated by the sun, warmer water rises to storage tank by convection
Name three disadvantages of solar water heaters
Expensive, low efficiency and hazard of transfer fluid leaks
What is a heat engine?
A heat engine takes in lower temperatures and produces higher temperatures
What are the types of solar concentrators?
Parabolic linear reflector, fresnel linear reflector, point focus tower and point focus dish
name three advantages of solar concentrators
good efficiency, fuel used is free, storage can be incorporated
name three disadvantages of solar concentrators
lots of land required, high construction cost, eyesore
What does a solar chimney consist of?
A collector slope, tall hollow chimney and wind turbines inside the chimney
What is a freshwater solar pond?
This is when water is trapped beneath insulating layers and a black layer
What is a saltwater gradient?
uses heat to cause a salinity difference where hot water can be extracted
Name three advantages of solar ponds
Simple to manufacture, can produce salt as a byproduct and reduced emissions
Name three disadvantages of solar ponds
Replacement of evaporated water, risk of transfer fluid leak and low efficiency
What is a closed ocean cycle?
Temperature difference of surface water and deep ocean is used, water is pumped from surface to evaporator to a heat exchanger to drive a turbine
What is an open ocean cycle
This is when surface water is in a vacuum to produce low pressure steam to turn a turbine
Name one advantage and disadvantage of ocean cycles
Advantage is producing fresh water and disadvantage is construction cost