BLOG: Blended Capacity: Firm vs. Intermittent
By Richard Payne, Managing Director, ReNew Petra
The truth about solar and wind renewable energy technologies is that when the sun isn’t shining or the wind isn’t blowing, renewable energy isn’t being produced. Without it, there’s no power to cool and heat our homes, stream our favorite shows, scroll through social media or charge our phones. Solar and wind power is called “intermittent power” because it is not always available, and perhaps more importantly, it is hard to predict its availability.
The opposite of intermittent power is “firm power.” Nuclear, natural gas and coal power plants are examples of stable and predictable firm power. Supplied with the proper feed stock, firm power is always available. For example, a natural gas power plant uses a virtually endless supply of natural gas by extracting it from the ground with hydraulic fracturing and other conventional technologies.
Since it would be a challenge for a robust and stable society to rely on intermittent power alone, many people have found ways to supplement intermittent solar and wind power with firm power. People like Elon Musk, inventor and genius behind Tesla, have brought the power of batteries to the forefront, but that idea seems less feasible once we take a look at the price tag. Until batteries are affordable enough to use in a blended capacity, they are not the most economical option for most residential and commercial applications.
So what do we do? Intermittent power from the sun and wind are clean and infinite, but not reliable and predictable for day-to-day use. Firm power keeps the lights on, but the creation of firm power causes pollution and poses as a detriment to our health.
This is where the concept of blended capacity comes in. The future of renewable energy is firm and beyond intermittent technologies alone like solar or wind. Blending solar with additional initiatives such as anaerobic digestors like landfill gas-to-energy keeps the lights on and substantially reduces pollution in the atmosphere. Moreover, firm renewables reuse existing waste and waste byproducts, and other renewable feed stocks.
What are these miracle sources of power? Let’s take a look:
- Anaerobic Digestors (aka Biogas): Believe it or not, we are able to produce energy through swine, poultry, cow, and even human waste by taking waste from farms and putting them into giant slurry domes. The wastes’ organic compounds break down into methane gas which is captured and sent to an engine to be convert into electricity. This is a similar process as the one used to convert natural gas to electricity. The biggest challenge with this form of biogas is getting all of this waste into one place so there is enough scale of usable methane gas.
- Landfill gas-to-energy (LFG): Our landfills have the same organic compounds needed to convert methane gas into energy. Leftover food is the primary usable compound, but it is mixed in with a lot of useless trash like Q-Tips, chairs and clothing. However, because landfills have such a massive concentration of trash in a single place, the methane yields are still adequate to supply to an engine and convert the gas into electricity.
What is the future for Firm Renewables?
By blending sources such as waste-to-energy or landfill gas-to-energy with solar we are able to create more sustainable and consistent sources of power. This can be a sustainable solution as more and more solar and wind developers sell their “intermittent power” to the grid through Purchase Power Agreements with utility companies like Duke Energy. The last thing that utility companies want to worry about is a lack of energy stability. By creating a solution for utility companies, we are able to power our everyday lives through the use of blended renewable energies.
Through the use of developing technologies to create firm renewable energy, we are able to supply our needs through the use of solar, wind and biogas technologies. It can be said with certainty that our future is renewable because seeing more-and-more that there may not be a future without it.
Also available on Richard Payne’s blog: https://medium.com/@thinkrichardpayne