Renewable energy penetration
“What do scientists mean when they talk of renewable energy penetration?”
Often times, scientists will mention a term called “renewable energy penetration” when discussing sustainable systems. Now, the name itself probably comes off as a tad bit confusing, so what exactly do they mean? Well, renewable energy penetration simply means the amount of power in the electric grid that is supplied by renewable sources. This term is not just a simple measure of energy generation but is a phenomenon that energy engineers, planners, and policymakers must focus their active attention on since a grid with a high renewable percentage will have to deal with novel effects such as the duck curve and microgrid integration.
The duck curve
“What happens when demand and generation from renewable energy is out of sync?”
There is one nagging bump on the road to achieving a truly sustainable society. The energy generated from renewable sources is not constant but varies throughout the day. Specifically, the peak power generation happens during noon, when the sun is shining the brightest, and the minimum occurs after sunset. However, Human energy consumption has a tendency to be the opposite, since individuals are away from their homes during noon and return in the evening. This means that grids with a high sustainable penetration rate often struggle to cope with this imbalance of supply and demand, which manifests itself as a duck curve. One way to fix this issue would be to invest into a large amount of energy storage such as batteries or vehicle to grid technology.
Vehicle to grid technology
“Could we use the batteries of electric vehicles to power our homes?”
Renewable energy has a problem. The peak times for generating such power (mid-day) is often not in sync with the peak stress on the grid (sunset, when solar energy is no longer available), and local battery storage can be quite expensive. So how can we circumvent this issue? Well, let’s use our engineering mindsets to solves this problem. One of the main problems stems from the lack of affordable energy storage. However, many sustainability conscious individuals also own electric vehicles. And in these electric vehicles are electric batteries which often times have excess energy. So what if when these cars were parked at night, they would feed energy back into the local smart grid to power homes? Well, this is the main idea behind a system which researchers refer to as vehicle to grid technology, which is not only environmentally friendly but economically with the use of net-metering.
How sustainable energy is better for job creation than fossil fuels
“When the data adds up, does sustainable energy result for more and better jobs than fossil fuels?”
One of the most common diatribes launched against investment in renewable energy is that such ventures are wastes of money which should go into more economically fossil fuels. However, instead of accepting such claims blindly, how about we act as scientists and analyze such claims empirically?
Well, it turns out that a group of individuals at the World Bank decided to conduct such a study for the United States. To measure the economic potential each form of energy (solar, wind, coal, etc.), data was strewn from the jobs created per million dollars of investment. From this data, it was found that not only are clean energy industries over twice as effective on average than fossil fuels but also result in a higher percentage of direct jobs. Needless to say, renewable energy is anything but the overpriced caricature that oil companies make it out to be, and is a most logical option for the United States. So please, if you are a citizen or resident of the country (or the world for that matter), please stand together to combat the nefarious attempts by the current administration to hamstring all efforts by joining in the upcoming March for Science.
A brief primer on coal’s demise
“Why is it that coal is on a pre-destined trajectory to decline?”
The current president of the United States has promised to return the dwindling coal industry back to it’s pre-post-industrial “glory days”, and has already taken action to lobotomize it’s supposed vanquisher, the EPA. However, despite Trump’s rhetoric, coal is on an inevitable decline regardless of action from regulatory agencies. Instead, the main agents for the decline of coal are simple economic and market factors.
Over a century of mining activity in the Appalachia region of the United States has resulted in a dearth of easy to reach coal. This causes the prices for said item to rise, hamstring their market competitiveness with the ever declining prices for renewable energy resources (which compose of two-thirds of all new generating capacity in the United States). Compounding this with growing international concern for climate change and a decreasing desire to use power supplies to contribute to it, the market for coal is shrinking ever more. So even with the environmental regulations set by the prior administration’s EPA, not much can be done to save coal. Instead of trying to resurrect a dying technology, the United states should move forward with adopting cleaner forms of energy, since a nation walks faster looking forward
How coal works and why it is bad
“How does coal make electricity and why should we not do it?”
Coal is the largest source of energy, powering over 40% of all of human civilization’s power consumption. However, how do these rocks from the ground provide so much for us and why do sustainability advocates warn us about how it’s harmful effects? Well, let’s take a look at how it is made to gain insight.
Coal itself forms from the remains of ancient trees and plants from thousands of years ago. Over time, the immense pressure of the Earth will cause them to carbonize, making them the rocky substances that we know. This process will ensure that coal will have a high energy density and flammability, so if it were to be burned a large amount of energy would be transferred.
Once mined from the planet, coal will be pressed into a powder and tossed into a furnace to power a fire, which will heat up a nearby container of water to boil into steam. This steam will then power a turbine that turns a generator to produce electricity. This electricity will then be sent to a transformer that passes it through transmission lines to reach a power consumer (such as a house).
Now, the fatal weakness with coal stems from the root of this process. Coal is composed of a multitude of dangerous hydrocarbons. When burned, these chemicals will be released to pollute the atmosphere, which will not only induce further global warming but also cause health hazards to nearby communities. That’s why countries all over the world are taking steps to reduce their reliance on coal and are switching to renewable energies instead.
Vertical axis wind turbines
“Can we make wind turbines to be placed on another axis?”
Wind turbines are famous for their horizontal axis rotor design, looking like giant fans in the distance. However, do things have to be this way, and could it be possible to shift the turbine onto another axis? Well, let’s think about it. We know that the wind is always blowing perpendicular to a post in the ground. We also know that this wind can exert a pushing force on objects in its direction and that if such an object was freely attached a solid post a torque would be induced that would cause it to move around said post. Now, what if we were to take this torque and have it spin a generator to make electricity? Well, this turns out to be the operating principle behind a vertical wind axis turbine. The symmetric design of vertical wind axis turbines (also known as VAWTs) allows them to not need to “track” the direction of the wind (as the machine would be affected equally in all directions), place less fatigue on the gearbox, and can possibly be more efficient than traditional wind turbines. However, VAWTs are also more failure prone, which could prove to be burdensome on a company’ economics.
Lithium ion batteries
“What exactly makes the type of batteries in your phone so special?”
You are probably hearing about special “lithium ion batteries” being featured in devices everywhere. But have you ever wondered what exactly makes them so special? Well, let’s take action and use our engineering mindset to figure this out. In contrast to traditional batteries, lithium ion batteries are constructed out of lithium and carbon. These elements are fairly light in nature, and lithium is also highly reactive, allowing these batteries to have a very high energy density. Quantitatively speaking, lithium-ion batteries can hold 150 watt hours in a single kilogram, only 1/6th of what is required for older lead acid batteries! Furthermore, Lithium Ion batteries lose their charge during storage at 1/4th of the rate other batteries do, can be recharged before being completely discharged, and can handle hundreds of charge/discharge cycles. This combination of high energy density and rechargeability makes lithium ion batteries terrific options to outfit mobile machines such as phones and cars. However, the same highly reactive property that makes them so effective with energy storage also causes structural instability, since they start degrading once they begin degrading once they leave the factory and can be very prone to unintended and dangerous heat-induced chemical reactions such as explosions.
“How can we make a convenient way to store energy harvested from the sun?”
Solar power is a most fascinating and practical way to capture energy. Just by taking in natural energy from the sun, it can power homes, buildings, and even entire towns! However, all of this comes with one drawback; Solar energy can only operate when the sun is out. This means that if machines want to operate during the dark, there will need to be some way to store this energy. Well, instead of giving up, let’s use our engineering mindset to solve this problem. We know that one method to store energy is one that is found every day, batteries. Batteries can have a high energy and also discharge with ease. So what if we were to hook up a solar panel system to a battery to create a solar battery? This setup is the exact working principle behind a multitude of innovative projects such as Tesla Motor’s powerwall system and grid islanding infrastructure.