GE and Southern California Edison recently worked on a project together to more efficiently ramp up generation in the evening when the sun is starting to set and people are coming home to turn everything on. My research assistant a.k.a. my mom just pointed me to this interesting new method that combines a lithium ion battery system with two existing natural gas turbines. The total output of the system will be 50 MWs, and they are calling it the LM6000.
Before there was so much solar and wind power on the grid, energy supply and demand were smoothly coordinated by slowly ramping up natural gas turbines for up to twelve hours. This process worked fine in the old days, but with today’s variable renewable energy sources it is a much bigger challenge. The traditional system of ramping up a gas turbine wasted a huge amount of fuel and therefore released a ton of carbon into the atmosphere. The reason for this is that traditional systems have to burn fuel for hours while they are is standby mode and waiting to connect to the grid.
With the LM6000 system SCE will be able to instantly begin discharging power from the energy stored in batteries while they ramp up the gas turbines. This system allows for much more flexibility then current technology because they can literally start providing energy supply in seconds as opposed to hours. This is going to add stability and reliability to the grid for all of the end customers. By having this capability SCE is also positioning itself to be able to acquire more solar Power Purchase Agreements (PPA) without fear of how to balance supply and demand. Another benefit to the new set up is that is that it can be economical because instead of wasting all of that fuel to start up the gas turbines now they just turn on the battery. Then as the gas turbines start ramping up. All of that energy can actually be sent into the grid instead of being wasted as heat.
If you are interested in more renewable energy information please follow me on twitter @EvanNWarner
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There is a new trend taking place with energy transmission and storage. Microgrids have a new take on how we can generate, store, and distribute our energy. This concept is making us all take another look at our mass centralized generation and distribution system.
Most of our electricity today comes from large coal or natural gas fired power plants. From this central power plant the electricity can travel hundreds of miles along transmission lines before it gets to your house. There are definitely some benefits to using this method of energy production. For one you can gain a lot of efficiency and cost saving by having one or two large turbines and generators. But there are also some problems with the current model. One problem that has always existed with form of distribution is that there are large costs associated with building and maintaining the transmission lines. Another problem is that when you transmit electricity over long distances of power lines, you can lose up to 3% of it in the form of heat and electromagnetic energy. A problem that is only recently being realized with this process is that traditional grids are not really designed to handle large swings in generation. Historically this was not a problem, but with all of the new solar and wind energy entering the grid, it is becoming more and more of an issue.
A microgrid is a small localized grid that can be used to power a community or even a college campus. Microgrids usually consist of some method of producing their own energy, and usually have a method of storing the energy for later use. Often the source of energy for these microgrids is some form of renewable energy such as wind or solar. There are some microgrids that generate electricity by burning one thing or another, but typically with these systems, they are able to capture the waste heat and use it for heating other buildings in the community. By using the waste heat, they are able to significantly increase the efficiency of the system. There are downsides if these types of grids just like with anything else. If you have multiple microgrids covering multiple areas there will be a lot of redundant equipment and therefore wasted resources.
Please leave me a comment and let me know what you think about microgrids.
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If you have been following my blog I think you will know that a key challenge to bringing renewable energy to mass market is storage. We have the ability to generate a huge amount of cheap solar energy during the day time, but we really struggle to deliver it at night time. One approach to solving this lies in battery storage. Battery storage has a lot of potential (no pun intended), but we are not able to store municipality levels of energy in batteries yet. Another method that is being tested to store energy is using compressed air. The idea is that we can compress air with electricity generated by solar panels during the day, and release it across a turbine at night time.
This is a clever idea and it does actually work. The problem is that every time we convert energy we lose some efficiency. Air compressors have notoriously low efficiencies which can be between 65% and 80%. This means that for every 10 KW you put into compressing air, you only get about 7 KW of usable air. At this point a reader might ask, “I thought we can’t create of destroy energy, so where does the rest of the energy go?” Great question, I’m glad you asked. You are correct that we can’t destroy energy in reality most air compressors lose a lot energy in the form of heat. All of the energy that is lost in the process of compressing and expanding air across a turbine makes it hard to remain economical.
But all hope is not lost for this method of storing energy. An innovative company called LightSail Energy seems to have figured out a better way. LightSail Energy uses technology that both compresses air for later use, and captures and stores the waste heat for later use. By capturing and storing the heat, LightSail is able to greatly increase the efficiency of the process. Which means they are able to make this type of project much more economical. Another nice thing about compressed air energy storage is that you can scale it up by storing air in large underground caverns.
This company really understood the root problem and came up with a viable solution to solve it. Keep an eye out for LightSail Energy in the future because they are doing a lot of things right. They recently received large rounds of funding from big investors including Bill Gates.
If you have any thoughts on this innovative new technology please share them in the comments section.
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CAES PC: https://www.pge.com/pge_global/local/images/data/en-us/about-pge/environment/what-we-are-doing/compressed-air-energy-storage/caes.jpg
It seems like the auto industry is heading towards a future of more electric and less gasoline. This is great for the quality of our air and our children’s air. It is also great for reducing the amount of carbon dioxide that we are putting in the atmosphere (assuming they get their electricity from renewable sources). But the coolest part about all of these electric cars taking over our driveways and garages is that they each have a battery built in to them. In a previous blog post I talked about one of the biggest barriers of solar and wind energy is that they fluctuate and we need storage to offset those fluctuations. Soon all of these electric cars will be plugged into the grid and they will communicate with it in order to give and take power as necessary.
Of course a majority of the time, cars will be taking power off the grid so that they can have fully charged batteries for the drive ahead. But it is also likely that when the sun goes down, a small fraction of the electricity stored in millions of cars will be used to pump up the electricity of the gird to supply the night time demand. If we make batteries that can serve multiple purposes such as powering our vehicles and balancing the grid, they become more cost effective and there is more incentive for people to buy them. Just investing in batteries to balance the grid and nothing else is a much tougher sell.
When cars become one with the grid, they will also be able stabilize sudden power failures or sudden spikes in power. Currently if some generating equipment goes offline, it can mean a power outage for customers in the affected area. With car batteries supplementing the grid, these bursts and shortfalls will all be smoothed out. There will be less power failures, and less need to rely on ramping natural gas turbines up and down.
Do your part, go out and buy a plug in electric vehicle today!
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Sun PC: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hires/2015/25-researcherss.jpg
According to the Energy Information Administration (EIA) 67% of the energy generated in the United States in 2015 was from fossil fuel sources. There are several reasons for this percentage including economic reasons, existing infrastructure reasons, legacy reasons, and an abundance of these resources in our own country. Another reason why fossil fuels make up such a large portion of our generation is because we have an inherent problem with some of the most well-known renewable resources. For Solar (.6% US energy) and Wind (4.7% of US energy) the problem is storage.
As everyone knows, the sun is only up for a certain number of hours each day. Unfortunately wind tends to also have patterns of high speeds and low speeds. In America we like our TVs and lights to turn on any time day or night, and we don’t want to be held prisoner to the cycles of the sun. That’s where storage comes in to play. If we really want these technologies to make up a larger portion of our energy then we have to be able to store the energy when we can collect it.
Recall from my second blog post we can’t create or destroy energy so if we want to store energy we have to convert it into a form that can be stored. One popular method of storing energy these days is in the form of lithium-ion batteries. These batteries are great for storing energy, but it is difficult do to it on an industrial scale. In other words it would be difficult to store enough energy to power a city with our current lithium-ion technology. Tesla is now producing a Lithium-ion battery that could be used for individual use in people’s homes. This might be one work around for the industrial scale problem.
There have been several other methods proposed that could be used to store energy. Some of them include pumping water up a hill during the day time and using it to power a hydroelectric dam at night time. You can compress huge amounts of air during the day time, and release it across wind turbines at night time. You can also use electricity to separate water into hydrogen and oxygen and later burn the hydrogen to create thermal energy. The reason that we don’t see more of these technologies being used commercially is that they all have really low efficiencies. Every time we convert energy from one form to another, we lose some energy due to inefficiencies. In the current market, companies are better off just selling the solar power when the sun is shining.
If you have some thoughts on this post or energy storage in general I would love to hear about them in the comments section below.
Photo credit: http://berc.berkeley.edu/wp-content/uploads/2015/02/energy_storage_2013_11-13-1.jpg