Mi-Grid Story

Lithium Ferro Phosphate batteries.

Are Lithium Batteries safe?

Hardly a day goes by without a news article about Lithium batteries exploding. This makes many people wonder if they are safe. The answer is more complicated because lithium batteries are complicated.

First, there are many different kinds of lithium batteries. The actual chemistry can change between batteries. For a review of lithium batteries, take a look to “Battery University”, and the different chemistries. Some “flavors” of Lithium battery are less likely to cause issues, even with poorer quality or abuse. It is all about the proper design and implementation.  Here is a chart reprinted from Battery University of the Pros and Cons:

Reviewing those advantages and disadvantages, we have high capacity batteries that require special circuits to be safe. The lithium battery voltage requires the battery use an electrolyte other than water. Typically, organic solvents are used. If the cells break, they release flammable liquids. Finally, battery charging is different than a constant voltage systems typical of other batteries.

There are three sources of failure: 1) Poor quality cells. 2) Poor or missing battery management / protection circuits. 3) Poor quality charging system. ANY battery, lithium or not, will suffer from the same issues. The difference is the flammable solvent.

In many cases, it is a stack up of multiple issues. Knock off devices, like the look-a-like “Hoverboard” devices, have lower quality components and are almost never tested to US or international safety standards. Samsung tried squeezing a larger capacity battery, that one in one-hundred thousand didn’t fit quite right, causing failure when over charged.

So are they safe? When built by quality companies, used in quality equipment with quality chargers and tested, they usually are.

Solar Power System: How To Convert RV To Solar Power

There has never been a better time to convert your RV to solar power. Going mobile into remote places, there are no hook ups for easy power. Solar Can provide your basic needs. And the price of solar has dropped to the point that it is easy to afford.

First things first

The most important thing to consider before self-powering your RV is energy efficiency. Every light bulb should be replaced with LEDs. All appliances should be selected for low power consumption. Anything that heats should be propane. It will cost less to replace energy efficient items than to power them with a bigger energy system

The Generator

Most boon-dockers use battery systems to power their essential needs. But they need to run a generator for the recharge the batteries. And to run larger appliances, the generator has to run all the time. This takes fuel and usually requires multiple fill-ups per day. And generators are noisy, possibly spoiling the whole reason for going remote.

Going Solar

A couple of solar panels, either hard mounted or setup when stopped, can recharge these basic battery systems. The typical system uses a charge controller between the battery and the panels. The charge controller disconnects the solar panels from the battery when they are full and at night. You are still limited to powering DC items.

Making AC power

The next step up is adding an inverter. Inverters take DC power, say from batteries, and convert it to AC power. This AC power, if the inverter is large enough, can power most of your AC needs, for example air conditioning. The issue with powering everything is the limit of the number of solar panels and the size of the batteries.

Getting it all together

What would be best is something that combines the best of each of the above. Solar to power DC and recharge batteries. An inverter to cover AC needs. And a generator for the times you need full power.

Tetra West Technology make Mi-Grid, a hybrid energy system. It combines solar panels, battery storage, inverter systems and a generator, all controlled by their patent pending energy management system. Solar panels supply DC power and recharge batteries during the day. The energy management system contains an inverter to power most of your AC appliances. And the automatically controlled generator starts up for large appliances and to re-charge the batteries if they get low.

And Mi-Grid is more affordable than you might think! Systems start at $4495 and include inverter / energy management system, high quality/long life deep cycle batteries and the automatic start generator. Solar panels are selected based on the configuration of your RV. Many models are available to match your needs.

Saves Time

When you’re out with your RV, playing with the generator is not top of the priority list. Mi-Grid allows you have full power, without the inconvenience of daily filling and weekly oil changes. Besides being messy and time consuming, the environmentally minded have to store the debris for proper disposal.

Saves money

Compared to running a generator alone, a typical Mi-Grid system reduces run-time and fuel consumption up to 90% or more. Generator refills become weekly events instead of multiple times per day. Reduced run reduces oil change, sparkplug and other maintenance activities, letting you enjoy your RV more. Finally, reduced run time extend the life of the generator. A Mi-Grid system can pay for itself in a little as 90 RV days!

For more details on how to convert RV to solar energy, please contact Tetra West Technology.

How does Mi-Grid Work?

Mi-Grid is most similar to an Off -Grid solar energy system. It takes solar energy and makes DC power. It uses this power to run an inverter, making AC power, or stores it in batteries, or both.

How does it Differ?
Mi-Grid also connects AC power from multiple sources, a generator and/or utility power. In-stead of an oversized battery bank and solar array, it uses the generator as a backup. Mi- Grid is about half the cost of a similar off-grid solar system.

How is that different from regular solar on houses?
“Standard” Solar energy systems installed on residential houses are usually called “Grid Tied” or “Utility Connected”. They simply convert the DC power from the solar panel to AC power. It is directly connected to house power. They do not store solar power. Either the solar power is used locally or it is sent to the utility.

Mi-Grid Saves 30% more
Mi-Grid doesn’t sell power to the utility. It saves all of the extra energy in the batteries to use later. If the utility pays less for your solar power than you pay them for electricity, you save 30% more than if you sell your power.

What if the power goes out?
With standard solar, if the utility system shuts down, so does the solar. This is for safety.
Mi-Grid can operate independent from the utility. During the day, a Mi-Grid system is disconnected from the utility. You won’t even notice an outage.

At night, Mi-Grid connects to utility power if the batteries are low. If the utility goes out, it automatically switches to the batteries. With the batteries low and the utility out, the generator automatically starts.
The Generator supplies power and recharges the batteries. Once the batteries are charged, the generator shuts off. On a stormy day, with the utility out and no sun, the generator may cycle several times.

How is Mi-Grid compared to a generator?
Without solar, Mi-Grid can reduce fuel consumption by 50%. It does this by running the Generator at a higher load for a shorter time. Add in the solar panels and Mi-Grid may use no fuel at all. It averages out to a 90% reduction in fuel and run time. Plus, backup generators come on after the power goes out.
Mi-Grid keeps the power on. Never lose power.

The Story of Mi-Grid

The problem
Mi-Grid started as most things do with a request from a client. Tetra West Solar was approached to help an agricultural concern in South America. They had multiple pumps in multiple locations, powered by diesel generators. The cost of the fuel plus delivery was quite high. They wanted a solar energy solution.

Standard Solar
The pumps would run from 12 hours, from 6AM to 6PM. The smallest pump was 30kW. This required a generator set of 75kW. Unfortunately, this also meant the generator ran about 40% load, not an efficiently. The cost to run the pumps, around $60,000-75,000 per year, depending on the price of diesel fuel. A full size off-grid solar energy system with 2 days of storage was a sizable capital investment. Too much to consider.

Solar Offset
The first idea was to add some supplemental solar. A Grid-Tie type system would be connected, but size to 90% of maximum power consumption at noon. Based on the modeling, the solar would produce about 64% of the power. But the generator would still run continually. Fuel consumption would be reduced by only 43%. There was also concern about a grid-tied solar system tied with a generator. It is not recommended, even on large systems. Some sort of diversion system would be needed if the pump shut down and the generator continued running.

Add in storage
The new idea, add storage. But how? Grid-Tie systems aren’t designed to store power. How do you know when the power needs to
be diverted?

Back to off-grid
Off-Grid systems have storage and can buffer the solar energy. But some can connect more energy sources than simply solar. Maybe wind, maybe a generator.

Energy Management
A way was needed to combine all of these disparate energy sources together. This was the birth of Mi-Grid. Multiple sources of power with a way to pick the least expensive, most reliable source at any moment.
With the energy storage, solar and control over the generator, the modeling showed a 90% reduction in fuel. Most of the fuel use came on cloudy days. Mi-Grid and more While Mi-Grid started as a system for off-grid, even utility power could be connected. Mi-Grid can replace standard grid-tied systems, but more features and multi-source reliability.

Save 30% more than Grid-Tied
As the grid-tied Mi-Grids were compared with standard grid-tied solar, it was found that keeping the power saved 30%.

Increased reliability
Standard Solar save money, but doesn’t help when the power goes out. Mi-Grid keeps the power on.

Never lose power
One problem with backup generators, you have to lose power before the generator turns on. With Mi-Grid, all power sources are monitored. Switching between sources occurs in 1/60th of a second, and there is always enough residual power to keep you on while the generator warms up.

Save energy
The battery bank isn’t just for solar. The generator only runs long enough to recharge the batteries. Saving energy saves money, reduces noise and makes the system more reliable.