Welcome to Exploring Renewable Energy Technology from Bounce Energy! Because the ERCOT portion of Texas can be thought of as a “walled garden,” renewable energy sources in Texas now make up a significant portion of the energy supply mix. It’s also a dynamic technology with new innovations, discoveries, and issues arising every week. Each month, we will examine the latest news in the industry to better understand what (if any) changes might come to the Texas energy supply.

Gilsonite: Asphalt that Powers Lithium Batteries

It sounds like the perfect combination for powering an electric vehicle — a lithium-ion battery with a pinch of asphalt in it that speeds up the charging cycle from two hours to five minutes. And another perk— the battery can’t blow up!

Okay, technically speaking the asphalt is not the same stuff used for paving streets. Rice University chemist James Tour added gilsonite to conductive graphene nanoribbons to create a substance to coat lithium-ion battery positive electrodes. These anodes are able to charge at an amazingly fast rate and do so repeatedly and remain stable.

Gilsonite is actually naturally occurring asphalt that comes from the Uintah Basin in northeastern Utah. It has also been shown by Tour’s lab that it can be used to cheaply remove CO₂ from natural gas at the wellhead. Gilsonite can absorb about 114% of its weight in carbon at ambient temperatures.

Mixing gilsonite with conductive graphene nanoribbons not only enhanced the charge rate and stability but also stopped the formation of dendrites in lithium batteries. Dendrites are lithium metal strands that form and grow inside lithium batteries. When the dendrites pierce the electrolyte separating the positive and negative sides of the battery, the dendrites can cause a short circuit resulting in fires or explosions. What Tour’s research team discovered is that the gilsonite/graphene actually takes up lithium and prevents the metal from growing dendrites. And since the gilsonite/graphene coating is a simple mixture, there’s no need for a complicated process of growing nanotubes or an expensive coating process.

How Can Waste Generate Energy?

Your holiday bird might be past caring but nevertheless, poultry occupies a position of power in the world today. Especially when it comes to generating power because world-wide, poultry production is becoming more industrialized —resulting in lots more waste creation. Getting rid of all that poultry waste is a growing problem.

The thing is, while guano is a very good fertilizer, it also makes a really good biofuel. The challenge is making the conversion process simple and convenient. One method, called “Hydrochar” or hydrothermal carbonization (HTC) may have something to crow about.

HTC involves treating the guano or biomass in the absence of air using high temperature (350°F to 480°F) and pressure (145 psi to 725 psi) in water for 30 minutes to 8 hours. The process creates a dense carbon product similar to coal that burns well.

Biochar, meanwhile, slowly heats the biomass to about 842°F in an oxygen free furnace. Both methods are forms of pyrolysis.

Researchers at Ben-Gurion University of the Negev in Israel compared emissions from both HTC processed guano and biochar processed guano. The HTC guano produced 24 percent higher net Energy generation, burning at temperatures that made it a replacement for coal. In fact, 10% of coal burned in power plants could be replaced with HTC guano. The hot burning HTC guano also reduced emissions of methane (CH₄) and ammonia (NH₃) — greenhouse gases that would otherwise enter the atmosphere through normal decomposition. On the downside, however, the fuel gave off increased amounts of CO and CO₂.

Can Bacteria can Power your Smartwatch?

Microbial fuel cell (MFC) technology has been around for over a decade. The process is pretty simple: you have a bacterial colony living on the negative electrode of a fuel cell oxidizing organic stuff and releasing electrons that flow out through the anode electrode, travel around an exterior circuit and return to the cathode electrode, completing the circuit.

With the growth of wearable technology, such as health-monitoring watches and other gear designed to track your vital signs, phones, or even medical implants, there’s a growing demand for compact systems that generate power for all of them. And you can’t get more compact that MFC.

But to make these type of MFC fuel cells work, it requires a certain type of bacteria that can use a certain type of food source. Of course, not all kinds of bacteria are people-friendly. Staphylococcus aureus might make a good fuel cell but it’s also really infectious and nasty when it mutates into MRSA (Methicillin-resistant Staphylococcus aureus). Obviously, you don’t want getting anywhere near you.

That may not be a problem anymore. Professor Seokheun Choi of Binghampton University has developed a textile-based MFC. Made of stretch fabric, it is powered by bacteria that feed off the stuff occurring naturally on human skin, like sweat. This makes this MFC battery technology sustainable and long lasting.

How powerful is it? According to Choi, “The device generated a maximum power of 6.4µW/cm2 and current density of 52µA/cm2, which are similar to other flexible paper-based microbial fuel cells.” And because the power device is printed onto the fabric it can withstand stretching and twisting and is also easy to batch-produce.