July 26, 2018
Published by outwalking
California was warned months ago that its electrical grid was in need of service, this is not only true of California but the infrastructure of the entire US is past due for an overhaul or replacement. The grid was originally built just after WWII and most of it is in excess of 40 years old, it was also built based on technology that is now considered obsolete.
40 years ago the population was about 200 million and currently it is about 330 million. There are also many more devices that require electricity than there was in the 1960s and 1970s. The point being is that the load on the grid is at least double of what it was when the grid was new. Over the past decade more power outages and brown outs are occurring, likely the frequency of these power disruptions will increase.
California grid operators are now asking for customers to limit their electricity usage to keep the system from overloading. A few years ago, California along with some other states started a program that allowed utilities to cut / reduce a household’s power in lieu of a cost benefit. I believe this was a way of trying to get users to cut usage so the utilities wouldn’t have to upgrade their infrastructure. The cost to upgrade the nation’s grid is estimated to cost a couple trillion. Moneywise it is obvious why they don’t want to upgrade the system.
Recently there has been a growth in the use of solar panels. Most of these systems are grid tied, a grid tied system doesn’t require energy storage as the power which is generated is uploaded to the grid. Grid tied systems are lower in cost than off grid systems, in order to have a some means of storing energy. There are several ways to store energy but the most common is probably with batteries. The addition of the batteries will almost double the cost of a solar system.
With the dilapidated and vulnerable condition of the grid, it is worth considering the additional cost if one can afford it. As I mentioned before, grid tied systems do not directly power your house. The power is uploaded to the grid but in some systems, the power generated can be diverted to an inverter and used without going through the grid. This is only available when the panels are active, during the night the panels are not active so any power needs to be supplied by the grid. If the grid is down, even a house equipped with solar panels will not have power at night.
A solar system equipped with onsite storage can be used at night and when the grid is down as it draws energy from the onsite energy storage.
June 14, 2018
Published by outwalking
So far this year, solar panels were up 13% despite the tariffs on imported PV panels. The prospectus for the remainder of the year remains upbeat. They predict that the growth for this year should be as good as 2017 and 2019 looks even better.
The tariff is stiff, starting at 30% and reducing 5% a year. They are set to expire in 2022. Offsetting the tariffs, there is still a 30% federal tax credit for solar developers.
The energy market is always in flux but today there is a strong push to move towards alternate energy sources. There are other choices like wind, hydro and geothermal but these other sources are not as consistent or as portable as solar.
Wind power’s drawbacks are the need for a tower to place a propeller and the wind is unpredictable. Since the generator is a mechanical part that is constantly in motion, one needs to allow for regular monitoring and maintenance of the equipment.
Hydro and geothermal’s drawback is that they can’t be set up at any location, both need to be situated by a energy source that they can draw power. For instance, a hydro electric power station needs to be located by moving water to harvest the energy of the flowing water and convert it to electricity.
January 17, 2018 (updated January 17, 2018)
Published by outwalking
Graphene is a sheet of carbon which is one atom thick. At the University of Central Florida they are working to improve the light absorption of this material. Graphene doesn’t do well at absorbing light, it absorbs about 2%.
Initially they tried to embed metal particles in the fabric but this did not improve the absorption rate. They came upon the idea of altering the shape of the material but not the composition of the material itself. They stamped a pattern onto the material creating an optical cavity. This cavity acted as something similar to an ‘infinity mirror’.
An infinity mirror is made by setting up two mirror facing each other. This has the effect of an image or in this case a beam of light striking on mirror and reflected to the opposite mirror. The opposite mirror will in turn reflect the beam back towards the first mirror. This results in the beam bouncing back and forth between the mirrors, thus the name, infinity mirror. As a side note, this is what happens in a diamond and is the reason a diamond sparkles. If you are interested, leave a comment and I will do a post on how diamonds sparkle.
With this optical cavity, the material was able to extract more of the light’s energy because instead of hitting the material once, it hit the material many times so the 2% absorption rate multiplied by the times the light beam hit it.
The new shape increased the absorption rate by more than 45% but they expect with further adjustments they can get the absorption rate up to about 90%. They also believe that with this technique they can adjust the frequency of light that is absorbed, also known as tunable.
This is an important discovery. This means you have the ability to filter out the wavelengths of light you don’t want to view. Just as an example, you can set it up to see only infrared light, this would make it usable as in a night vision scope. This is just one example because it can be use for a myriad of applications.