5. Renewable Energy Technologies

Question 1

What are Battery Energy Storage Systems (BESS), and what is their role in renewable energy?

Answer 1

BESS are systems used to store electrical energy from various sources, including renewables like solar and wind. They store excess energy when supply exceeds demand and release it when needed (production is low - at night or on calm days).

BESS is crucial in integrating intermittent renewable sources into the grid, providing grid stabilization, reliability, peak shaving, load shifting, and emergency backup power.

Question 2

What are the differences between fixed and floating wind in renewable energy?

Answer 2

Fixed wind turbines are mounted on structures secured to the seabed, suitable for shallower waters and representing a more mature, cost-effective technology.

Floating wind turbines, mounted on floating structures tethered to the seabed, can be deployed in deeper waters, offering flexibility in location and reduced visual and environmental impact.

Floating wind is an emerging technology with currently higher costs than fixed wind.

Question 3

What are offtakers in renewable energy?

Answer 3

Offtakers are entities that agree to purchase electricity from renewable energy projects. They play a crucial role in providing a market for electricity generated by renewable sources like wind farms and solar parks.

Question 4

What is electrolysis and how is it used in producing green hydrogen?

Answer 4

Electrolysis is a chemical process that uses electricity to split water (H2O) into hydrogen (H2) and oxygen (O2). In an electrolyzer, water reacts at two electrodes (an anode and a cathode), generating hydrogen at the cathode and oxygen at the anode.

For green hydrogen production, this process must be powered by renewable energy sources like solar, wind, or hydro power, making it environmentally friendly as it doesn’t emit greenhouse gases and the only byproduct is water vapor.

Question 5

What is green hydrogen and how is it produced?

Answer 5

Green hydrogen is produced by electrolyzing water using renewable energy sources. It is considered a clean fuel as its production doesn’t involve fossil fuels, and its use only emits water vapor, making it environmentally friendly.

Question 6

What are eFuels, and how are they different from green hydrogen?

Answer 6

eFuels or Electrofuels are synthetic fuels made by combining hydrogen (often green hydrogen) with carbon dioxide, using renewable electricity. Unlike green hydrogen used in fuel cells or modified engines, eFuels can replace conventional fossil fuels in existing engines and infrastructure. Examples include synthetic methane, gasoline, diesel, and jet fuel.

Question 7

What are hybrid renewable energy systems and their advantages?

Answer 7

Hybrid renewable energy systems integrate two or more different renewable energy sources, like solar and wind, to enhance energy efficiency and reliability. They offer improved reliability and efficiency, especially in off-grid areas, by using complementary energy sources and often include energy storage solutions.

Question 8

What is biomass in renewable energy, and what are its types?

Answer 8

Biomass is organic material from plants and animals used as an energy source. Types include woody biomass (forest debris, wood chips), agricultural biomass (crop residues), energy crops (like switchgrass), and organic waste (food waste, animal manure). It’s renewable due to its replenishable nature and sustainable production methods.

Question 9

How is biomass converted into energy?

Answer 9

Biomass is converted into energy through various methods:

Direct Combustion: Burning biomass to produce heat for electricity or heating.
Anaerobic Digestion: Breaking down organic matter to produce biogas.
Fermentation: Converting biomass into ethanol.
Gasification and Pyrolysis: Transforming biomass into syngas or bio-oil for fuel or chemical feedstocks.

Question 10

What is shadow flicker and its impact in the context of renewable energy, especially wind turbines?

Answer 10

Shadow flicker refers to the effect produced when rotating wind turbine blades periodically cast shadows over a nearby area, creating a flickering effect. This can occur in areas close to wind farms when sunlight passes through the moving blades.

The impact of shadow flicker is usually considered in the planning and development of wind farms, as it can be a nuisance to nearby residents. Mitigating measures include careful siting of turbines, considering the sun’s path, and sometimes using technology to predict and minimize the impact.

Question 11

What are turbine ratings, and why are they important in renewable energy?

Answer 11

Turbine ratings refer to the maximum power output that a wind turbine or other types of turbines (like hydro or steam turbines) can produce under ideal conditions, measured in megawatts (MW).

Question 12

What is Vortex in the context of wind energy, and how is it used?

Answer 12

Vortex is a modelling tool used in wind energy to predict wind patterns and potential energy output at wind farm sites. It uses weather data and algorithms to help choose sites, place turbines, and estimate how much energy a wind farm can produce. Vortex is key for designing efficient wind farms and maximizing their energy production.

Question 13

What is Flex Gen in the context of renewable energy, and why is it significant?

Answer 13

Flex Gen, or Flexible Generation, refers to power generation systems that can quickly adjust their output to match the demand in the electricity grid. This is particularly important in renewable energy, where sources like wind and solar are intermittent.

Flex Gen technologies, such as gas peaker plants or battery storage systems, provide essential grid stability by compensating for fluctuations in renewable energy generation.

Question 14

What is the role of thermal energy in the context of renewable energy?

Answer 14

Thermal energy refers to the heat energy generated and used for power production or heating purposes. It can be derived from renewable sources like geothermal energy, solar thermal technology, and biomass.

In the renewable energy sector, thermal energy projects are significant for their ability to provide consistent and controllable energy, complementing intermittent sources like wind and solar.

Question 15

What is Long Duration Energy Storage (LDES)?

Answer 15

Long Duration Energy Storage (LDES) refers to energy storage systems that can store electricity for extended periods, typically hours to days. LDES is crucial in renewable energy for balancing the intermittency of renewable sources. It allows for the consistent and reliable delivery of energy, even when renewable generation is low. LDES technologies include pumped hydro storage, flow batteries, and mechanical storage systems.

Question 16

What are Independent Power Producers (IPPs) and their role in renewable energy and M&A?

Answer 16

Independent Power Producers (IPPs) are private entities that own and operate facilities to generate electric power for sale to utilities, governments, or directly to the public. In renewable energy, IPPs are crucial as they often lead the development of new projects like wind farms, solar parks, or biomass plants. They contribute significantly to the diversification and growth of the renewable energy sector.

Question 17

What is a PVsyst Report in the context of solar energy?

Answer 17

A PVsyst Report is generated by PVsyst software, which is used for the simulation and analysis of photovoltaic (solar) systems. The report provides detailed projections and analyses of a solar energy project’s performance, including expected energy production, efficiency, and financial feasibility. It considers factors like geographical location, type of solar panels, inverter efficiency, and shading.

In solar energy projects and M&A, a PVsyst Report is crucial for assessing the technical viability and economic potential of solar installations, influencing investment and development decisions.

Question 18

What is irradiance data and its significance in renewable energy?

Answer 18

Irradiance data refers to the measurement of solar power received per unit area, typically expressed in kilowatts per square meter (kW/m²). This data is crucial in the (particularly for solar energy projects) as it determines the potential solar energy that can be harnessed at a specific location. Accurate irradiance data is essential for designing solar power systems, estimating energy yield, and conducting feasibility studies.

Question 19

What are downstream turbines in the context of wind energy?

Answer 19

In wind energy, downstream turbines refer to wind turbines that are located behind other turbines relative to the prevailing wind direction. They are significant because they can be affected by the wake effect, where turbulence and reduced wind speed caused by upstream turbines can decrease their efficiency and energy output.

Understanding the placement and impact on downstream turbines is crucial for optimizing wind farm layouts to minimize wake effects and maximize overall energy production.

Question 20

What does MWdc stand for in renewable energy?

Answer 20

MWdc stands for Megawatt direct current (MWdc), a unit of power measurement used to quantify the output or capacity of direct current (DC) energy sources, such as solar photovoltaic (PV) systems. It indicates the total power capacity of solar panels under standard test conditions before conversion to alternating current (AC) for grid use. MWdc is important in renewable energy for sizing solar installations and estimating their maximum DC power output under optimal conditions.

Question 21

What does blade degradation mean?

Answer 21

Blade degradation refers to the decline in performance and structural integrity of blades used in various applications, such as wind turbines and engines, due to environmental conditions, operational stresses, and manufacturing defects.

Question 22

What does albedo mean?

Answer 22

Albedo is a measure of a surface’s reflectivity, indicating how much sunlight is reflected versus absorbed. It is expressed as a percentage or a fraction, ranging from 0 to 1, where 0 represents a perfectly absorbent (black) surface that absorbs all sunlight, and 1 represents a perfectly reflective (white) surface that reflects all sunlight.

It influences Earth’s energy balance and climate. Surfaces with high albedo, such as snow, ice, and some cloud types, can reflect a significant portion of incoming solar radiation back into space, thus having a cooling effect on the Earth’s surface. Conversely, darker surfaces, such as forests, oceans, and urban areas, have lower albedos, meaning they absorb more solar energy, which can contribute to the warming of the Earth’s surface.

Question 23

What is the AC/DC ratio in the context of photovoltaic (PV) solar power systems?

Answer 23

The AC/DC ratio, also known as the inverter load ratio (ILR), is the ratio between the total installed capacity of photovoltaic panels (DC capacity) and the total rated capacity of the inverter(s) (AC capacity) in a solar power system. It is key for designing and optimizing system performance.

A higher ratio indicates more panels connected to the inverter than its nominal capacity, affecting energy production and power clipping during peak times. The optimal AC/DC ratio balances capital costs, operational efficiency, and energy yield, varying based on location, irradiance, and economic factors.