Renewable Energy

**Statement 1 is correct.** Bagasse: This fibrous residue left after sugarcane juice extraction is a valuable biomass fuel. It can be burned to generate electricity or heat, often powering the sugar mills themselves. **Statement 2 is incorrect.** Synthetic Fertilizers: Molasses don't directly contribute to the production of synthetic chemical fertilizers. These fertilizers are typically manufactured using chemical processes involving elements like nitrogen, phosphorus, and potassium. **Statement 3 is correct.** Molasses: While molasses isn't directly used to produce synthetic fertilizers, it can be fermented to create ethanol, a biofuel. Ethanol can be used as a transportation fuel or blended with gasoline. Thus, statements 1 & 3 are correct while statement 2 is wrong.

**Statement 1 is incorrect.** The production of algae-based biofuels is not limited to seas only. It can be done on land, saline water, or wastewater. **Statement 2 is correct.** Setting up and engineering the algae-based biofuel production does require a high level of expertise/technology, which might be a limitation for developing countries. **Statement 3 is also correct.** Economically viable production of algae-based biofuels does necessitate the setting up of large-scale facilities, which may raise ecological and social concerns. 

Pumped-storage hydropower (PSH) is used for long-duration energy storage. It works by pumping water to a higher reservoir during low electricity demand and releasing it to generate power during peak demand. This process helps balance the grid supply and demand, making PSH an effective tool for energy storage over extended periods. **Thus, the correct answer is C**.

Distributed Energy Resources (DERs) are small-scale units of power generation or storage that are situated closer to the end-users. Let's analyze each option: * **Battery storage:** These store energy and can be deployed within the distribution network or at the consumer end, making them DERs. * **Biomass generators:** These can be small-scale and located near the biomass source, making them suitable for distributed generation. * **Fuel cells:** Similar to biomass generators, fuel cells can be deployed in a decentralized manner, qualifying as DERs. * **Rooftop solar photovoltaic units:** These are a classic example of DERs, generating power at the point of consumption. _Therefore, all four options are considered Distributed Energy Resources._