Implementation of Complete Renewable Power Grid

 Courtesy: Md. Aminul Hoque, Batch-201, Dept. of EEE, Green University of Bangladesh

We often hear about renewable energy but not about power grids powered by renewable energy. Why it seems impossible or we don't want to think. To me, we can create a completely renewable energy grid  by renewable sources. Here are my thoughts on it. Let's first understand why we need a renewable power grid.

Why should we have a renewable grid?

Building a renewable power grid would be a step towards a world free of fossil fuels. It will help us to study and increase knowledge about renewables. A breakthrough would bring many renewable power grids to the world. Which will speed us towards a carbon free green world. Again, this will reduce our dependence on fossil fuels and strengthen our economy. Countries dependent on other countries for fossil fuels will be freed from this curse. Thus, it can give this world a strong economic balance.

A Renewable Energy Source:

1) Solar

2) Air

3) Geo Thermal.

4) Biomass

5) Hydropower

6) Foot step strength.

7) Nuclear power.

8) River power.

9) Water fall force.

10) See water power.

11) Using gravity

Contraction:

To build a fully renewable energy powered power grid we first need to understand the issues with renewable sources.

Renewable Issues:

1) Storage

2) Time dependence.

3) Unstable power supply

4) Low efficiency. (It can be increased by material improvement or mechanical improvement or better design.)

5) Consider space.

6) Transport system.

7) Variation of power (AC and DC)

Things we need to keep in mind:

1) Calculation of electrical load

2) Selection of inverter

3) Selection of storage system

4) Source selection

Storing electrical energy is not easy. Scientists all over the world cannot give us a solution to store a large amount of electrical energy in a small space. Batteries are obviously a very efficient power storage system, but battery production is not very environmentally friendly. We have to mine the earth for battery material, which leads to air pollution by diesel or patrol vehicles and has a lasting impact on nature. So, we can use mechanical storage system. In my opinion using hydro power plant as storage system is very ecofriendly and efficient for this purpose. As such, our electric motors have efficiency levels between 70 and 98% (let me get to that later). So, we can easily build existing hydropower plants as storage systems and build new ones without wasting money on building large battery storage systems. We know the average lifespan of a batter is 20 years. After that we have to replace them with new ones. Where we can use a hydroelectric plant for about 150 years. Batteries may have other applications such as electronic devices, homes, electric vehicles, drones, etc. But it is very inefficient as a storage system to build a renewable power grid.

How the grid will work:

As with conventional power plants, we cannot turn off energy from a source in a renewable power grid system. Therefore, I propose a system that consists of a series of alternators that will allow us to both store power when power is available and generate power when needed. This set of alternators will be controlled by an advance system. When the grid power is increasing, the system will turn on the alternator as the load. Thus, the power surge in the grid will be balanced and by acting as a motor, it will pump water from lower reserve storage to higher reserve storage. Again, when the grid power is running low the system will turn on the alternator as a generator, thus increasing the power as needed. This entire system will stabilize the grid and create the possibility of uninterrupted power supply at all times. Here comes a motor skill. As I said before, our electric motors have an efficiency level between 70 and 96%. Hence, the storage energy loss during hydropower generation is minimal. Thus, the system can easily store a large amount of energy for later use with a great efficiency.

Secondary Back Up System:

The grid will be built with two storage systems. A permanent and to be used only in emergency. The other will be used daily or quiet often. We will use hydroelectric power plant as daily storage system. A set of options for capacity conservation or capacity building will be attached to it. For our permanent energy storage, we will use biomass energy. We will store methane from biomass. Then we will transfer it to the power plant and store it as LNG. This LNG will be used at the most critical times. As such, the hydropower plant loses its water reserves and all sources are not providing enough power to recover the lost water and the grid power demand is also increasing. In this case the secondary plant will supply power to the grid until the hydroelectric plant is operational again.

Critical stock strength

We will stock up enough LNG to produce the required power for 30 days. This LNG will be ready for any emergency situation. We will make this LNG from agricultural waste like cow, animal dung. We will not use life stock such as corn or other crops. This way, our LNG will be 100% pure and we won't have to worry about food safety.

Total Power Supply Scam:

I will take my native Bangladesh as an example. We have a hydro power plant with a capacity of 6,477,000,000 m3. It is capable of generating 230 MW of electricity. Hydro generation per year: 982 GWh Technically feasible hydro generation per year: 1,500 GWh. Its catchment area is about 11,000 km2 (4,200 sq mi). If we take 60% of this area and replace it with solar panels it will cover about 6600 km2 or 6.6*10^9 m2. Now if we cover the area with 1 M2 panels that produce 63 W each. Then the total amount of power would be 4.158*10^11 W or 415.8 GW. This is just one part of our system. If we combine wind, river and sea water energy, it will be a huge amount of energy and the grid will be strong enough to power a part of the country.

Cost Management:

Building a fully renewable power grid can be expensive. But it is actually very cheap for long term. Because it is only one-time investment project. Unlike conventional coal or gas power plants, no additional fuel is required to run the plant. Thus, it saves a huge amount of extra money to build the system.

Why would we need one?

1) Fossil fuel prices are increasing day by day.

2) It is pollution free power grid.

3) Can give us continuous supply for long time.

4) No additional fuel is needed to power it.

5) It will sustain it as the future as long as the earth lasts.