Renewable Energy Systems Flashcards
7 cards from real CEM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Renewable Energy Systems flashcards as text
In a grid-tied solar PV system, what is the primary function of the inverter?
Answer: Convert DC power from solar panels into AC power compatible with the building and grid
The inverter is the core power conversion device in a grid-tied PV system, converting variable DC output from the panels into AC power that matches grid voltage and frequency.
What is the wind speed at which a wind turbine first begins generating electricity called?
Answer: Cut-in speed
The cut-in speed is the minimum wind speed at which the turbine begins producing usable power; below this speed, wind energy is insufficient to overcome mechanical losses.
Which type of solar thermal collector is most appropriate and cost-effective for low-temperature applications such as swimming pool heating?
Answer: Unglazed flat-plate collector
Unglazed flat-plate collectors are simple, inexpensive, and well-suited for pool heating, which only requires raising water temperature a few degrees above ambient.
What does the metric 'peak sun hours' represent for a solar installation site?
Answer: The equivalent daily hours at 1,000 W/m² irradiance that delivers the same energy as actual daily solar radiation
Peak sun hours normalize the daily solar resource by converting total daily irradiation into equivalent hours at the 1,000 W/m² standard test condition irradiance.
Which statement best describes a biomass energy system?
Answer: Combusting or thermochemically converting organic materials to produce heat or electricity
Biomass energy involves burning or thermochemically processing organic materials — such as wood, agricultural residues, or energy crops — to generate heat or electricity.
What is the primary operational advantage of a run-of-river microhydro system compared to wind or solar installations?
Answer: Ability to generate consistent baseload power 24 hours a day from continuous water flow
Microhydro systems produce reliable, near-continuous electricity as long as adequate stream flow is available, unlike solar and wind which are intermittent and weather-dependent.
What is the primary purpose of a solar charge controller in a stand-alone off-grid PV system?
Answer: Regulate charging current to batteries and prevent overcharging or excessive discharge
A charge controller manages current flow between the solar array and the battery bank, preventing overcharging that causes damage and over-discharging that reduces battery lifespan.