Mi-Grid Energy

Battery Options for Mi-Grid

We are often asked, “What kind of batteries do you use?” Mi-Grid systems are offered with 3 choices:

High-Quality Absorb Glass Mat (AGM) batteries
Advanced Lead Acid – Nano Carbon batteries
Lithium

AGM

Absorb Glass Mat (AGM) batteries

Our standard offering uses high-quality AGM batteries. For a system where the batteries are a backup, or are not cycled very often, our standard AGM is the most cost-effective. AGM batteries are a form of lead acid battery. Instead of liquid sulphuric acid, the battery is filled with fiberglass mat and the mat is made “wet.” This allows the battery to be mounted in any direction, and there is no chance of spilling. If the battery case were damaged, it may dry out, but the acid fluid cannot leak. These are considered, “non-hazardous”.

For Mi-Grid systems connected to utility power, the batteries are kept full. Only when the utility power fails will the batteries be cycled. These batteries are also used wherever the system is set up for up to 80% depth of discharge (what percent of the total battery is used). AGM batteries, if treated properly should last a minimum of 5 years, possibly as long as 10 years.

Nano-Carbon

Nano-Carbon batteries

Nano Carbon batteries are called “Advanced Lead Acid.” The ones we use are also an AGM battery with all of the benefits. The internal parts of the battery are covered with a nanoparticle carbon coating. This increases the life of the battery in places where it cycles a lot. The batteries operate best in a “partial state of charge.” The controls are reprogrammed to operate the battery in the middle of its range and the usable portion is about 50-60% of “full” capacity. This is how they are able to achieve 3000 cycles.

These are great in high-cycling applications, where the batteries are charged and discharged every day, possibly more than once a day. They cost about 30% more than the regular AGM batteries. Great applications for these are off-grid, grid-connected cycling and mobile applications, such as food trucks and RVs.

Lithium

Lithium Ferro Phosphate batteries.

Lithium batteries, depending on the type, offer light-weight, smaller batteries with very high-cycle life. There are many types of lithium batteries. The type in your phone is typically Lithium Cobalt, due to the very high energy density. They are limited to about 500 charge-discharge cycles before losing significant capacity.

We use Lithium Ferro Phosphate batteries. They have a lower energy density (size vs. charge), but much higher cycle life. When used correctly, they may exceed 10,000 cycles! Typical is 5000-7000 cycles. For the same usable charge, they are about 2.5 times the cost of nano-carbon batteries. With the higher cycle life, they are comparative to the nano-carbon. You may never have to replace these batteries! They are also smaller and weigh about 60-70% less than either AGM battery.

These are best in high-cycle, mobile and applications in places where you do not want to change the batteries often. The prices are coming down, so these will probably be the best replacement battery, when the time comes.

Every type of battery has its place. I would say the Lithium batteries are “best.” But you may not want to pay that much at the beginning. If the batteries are in a grid-tied type system, the regular AGM batteries are best. The nano-carbons are the most cost-effective in a cycling application.

Update: The lithium batteries continue to fall in price, including LiFePo4. If you take into account the life of the battery, LiFePo4 is now cheaper than any form of lead-acid.

Mi-Grid Can Connect with Either AC or DC Coupling for Solar

We design our microgrids with flexibility in mind. For instance, Mi-Grid can be installed with either AC or DC power coupling. We can power you either way. Our systems can work with solar or wind power too.

AC VS. DC COUPLING MI-GRID

Mi-Grid AC vs. DC

Solar panels can be connected to Mi-Grid in two different ways. They can be DC coupled or AC coupled. Coupling is simply the term we use for the connection of the solar panels to the Mi- Grid system.

Mi-Grid—DC

DC coupling is the traditional way to connect solar panels to the Mi-Grid system. It is also the most efficient. Solar panels are DC (Direct Current), like a battery. It is easiest and most efficient to keep the power DC when storing to the batteries.

Mi-Grid—AC

AC coupling means the power is converted to Alternating Current, like your household power, before connecting to the Mi-Grid system. This means Mi-Grid can be retrofitted onto existing grid-tied solar systems. The advantage is a more simple installation of the solar array.

Which is better?

For Off-Grid systems, where efficiency is extremely important, DC coupling is definitely preferred. With most Grid-Tied applications, the efficiency loss only shows up when the utility is offline. And AC coupling allows a larger solar array to be connected to a smaller inverter battery system, maximizing savings, while reducing installed cost.

Retrofit systems connect the Mi-Grid system with AC coupling. With little change to a standard grid-tied system, you gain peace of mind with battery storage and generator backup. Mi-Grid keeps you going.

AC vs. DC cost

At the time of a new installation, similar AC and DC systems are nearly the same cost.

Where the budget is constrained, an AC coupled essential system is best. The system can be upgraded later if more inverter power is needed.

DC systems are best when off-grid. Efficient storage of the energy provides the most predictable power around the clock.

Looking to build a custom solar power? Great, get in touch with our engineers by submitting a form with your specifications and needs here.

How a Mi-Grid microgrid can be configured with AC power.

Diagram of a Mi-Grid coupled with AC power.

Mi-Grid Systems: How Our Models Are Sized for Different Applications

Our microgrids can be sized for any amount of demand and our Mi-Grid systems are configured for different applications, including residential, business and mobile (RVs, food trucks, etc.). Originally designed for off-shore platforms, we have systems configured from 2kW to 2MW!

Standard Models

Mi-Grid’s have 5 standard models. Even the “standard” models have options. They are configured based on size to match the demand (power load). Pricing can vary, some customers already own a component of the Mi-Grid system, such as a generator or a solar array.

Models also range in price depending configuration and options. Is the system grid-tied or off-grid? Is it AC or DC coupled to the solar panels? Is it applied to an appropriately sized dwelling for that model’s design or is a smaller-sized system applied to a larger dwelling, requiring additional sources of energy, i.e. a larger generator.

Other cost variables include installation costs, shipping, taxes and possibly duties. For each model below, we provide a price range, which does not include solar arrays and installation. As for the installed cost of solar panels, including mounting hardware and labor, that can range from $2.00-$4.00 per Watt, in the continental United States. Depending on where it is installed, there may be additional charges for shipping and duties. All price estimates provided here are in USD and for installations in the continental United States. These estimates are approximate as of January 2018.

Mi-Grid is an energy management system, meaning, at its core, it has a heart (hardware, controls and modules ) and a brain (software combined with our proprietary engineering design and safety considerations). All components are tested and certified to UL standards.

Mi-Grid 2000

Mi-Grid 250 & 500:

Both of these systems are 120VAC, single phase. They are DC coupled and were designed for off-grid. They are the least expensive/most cost-effective systems. They can be grid-tied, but cannot export/sell power.

Mi-Grid—250:

Tiny, but fierce! The main unit is 36” x 24” x 16”, and the batteries are inside! It is 2200 Watts and will power lights, outlets and a small window Air Conditioner. Up to 1.2kW of solar panels can be connected. Price range: $4,500 – $6,500, with standard batteries.

Mi-Grid—500:

Probably the most cost-effective system. The main unit is 48” x 24” x 16”, and the batteries are inside! It is 4000 Watts and will power lights, outlets and up to 1 large or 2 small mini-split Air Conditioners. Up to 3 kW of Solar can be connected. Price range: $7,500 – $10,000

Mi-Grid—1000-4000:

120/240VAC. The generator is typically a home-style propane/natural gas unit and can be “oversized” to power more external equipment. Solar can be AC or DC coupled.

Mi-Grid—1000:

Similar power to a Mi-Grid 500, but split-phase 240VAC and can connect up to 8kW AC Coupled (6kW DC coupled) of solar. Price range: $14,000 – $22,000

Mi-Grid—2000:

Same as a Mi-Grid 1000, but 8kW of power output. Price range: $21,000 – $30,000

Mi-Grid—4000:

A double unit Mi-Grid 2000, 16kW of power output. And up to 20kW of solar. $40,000 – $65,000 (The $65,000 unit includes a 48 kW generator!!!)

Which is better?

For Off-Grid systems, any system can work.

If 120VAC only will work for you, then the Mi-Grid 250 and 500 are very cost-effective.

For grid-tied, generally where you might sell excess power or if you have an existing grid-tied system, the Mi-Grid 1000-4000 are best.

If you need 240VAC power, you must choose a Mi-Grid 1000-4000.

Options:

All systems may have a larger generator. It will allow more items to be powered when the generator runs. And some items can be setup to be powered only when the generator runs
Any System can be purchased without a generator. Only remote startable generators can be controlled by a Mi-Grid. Most home type permanently installed generators can be controlled. A limited number of portable type generators can be controlled.
More batteries and more solar (up to a point!) can be added for longer run time without generator help.
Systems with limited solar can still be useful minimizing generator run time and fuel consumption.
Special Lithium batteries can be used which have 3 times the life of our best Advanced AGM batteries. Expensive, but in the long run, cost effective.

For more information, Contact us or a local Representative.

Never Lose Power

Today I did a one year inspection on a Mi-Grid 4000. This is primarily a check on the batteries and to do the yearly maintenance on the generator. With the exception of a few dead bugs inside the generator enclosure (how did that cricket get into the air cleaner?!?), it looked as good as the day it started it up.

One anecdote from the Owner. Earlier in the year, there was a terrible storm. They thought nothing of it. There was one flicker of the lights, but that was it. The next day, he attended a local luncheon where the primary topic was the 5-6 hour electric outage. He looked dumbfounded and said: “What Outage?”.

EXACTLY!!! With Mi-Grid, you never lose power.

If Mi-Grid is setup in UPS/Backup mode, and the utility goes out, it switches in less than a second to the inverter and batteries. If the batteries become depleted, the generator starts up and comes to full speed, THEN it switches over. You don’t lose power. And when the Generator finishes charging the batteries? It switches back to inverter BEFORE the generator shuts down.

With Mi-Grid, you simply never lose power!

Are Lithium Batteries safe?

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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.

Power Gen International 2016

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Tetra West and Mi-Grid will be in Orlando Next week (December 13-15, 2016) for the Power Generation International (PGI 2016). See us in the Texas booth, #4669

Mi-Grid is a Hybrid Solar Energy System, combining solar with energy storage and a backup generator. Mi-Grid makes renewable energy reliable! Grid-Tied, Off-Grid what-ever you need! Never lose power!

http://www.power-gen.com/index.html

Getting ready for a Hurricane – from Mi-Grid

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I live in the Gulf Coast area and hurricane preparedness is extremely important. About every 10 years, my area is hit with a hurricane, tropical storm or other disasters. It is much more important to prepare ahead, than wait until the announcement by the weather forecasters.

Run or Hide?

The saying is run from the water, hide from the wind. It means if your area will flood, get out of there! If your area won’t flood, you can “hunker down”, protect yourself and generally stay in your area.

Run from the water. Flooding is no joke. There isn’t anything you can do except evacuate. If you are in a flood-prone area, your preparedness is to have an inland location in mind, and your irreplaceable items “ready” to go. Know your evacuation route. Consider side roads and county roads which the rest of the public are not familiar. Keep extra fuel handy since there is usually a run on fuel just before the storm. Be prepared with a few days of food and water, since it may take time to evacuate. Remember, there will be LOTS of other people, so it will take much more time to get out of your area than normal.

Hide from the wind. Most people should stay where they are. First, the roads will be clogged with the people who need to evacuate. People in areas which won’t flood do not need to leave. If they do, they make the evacuation routes worse. So stay if you are not in a flood-prone area.

What do you need if you will be in a place to stay?

Food, water, and shelter. Your house is generally enough for shelter. If you are inland, the winds may be strong, but they generally not high enough to destroy your house. Most serious damage is storm surge and flooding. You may consider boarding up windows. Focus on the south and east windows, as this is usually where the wind comes from. Also look around your yard and remove anything which the wind can move. If you have a pool, tables and chairs can go in the water.

Food and water. Most people think they need bottled water. The water that comes out of your tap is EXCELLENT. But the power may be out and the water pumps off. So store water. How? Trash cans. Buy new ones!!! And you might want to put line them with trash bags. You also want to fill bathtubs and have a small bucket for pouring into toilets for flushing. Just buy the trash cans early and store them away unused.

Food you have a lot of choices if you prepare ahead. You can buy survival food. Not super tasty, but it is better than nothing. You can buy canned food. If anything needs heat to prepare, make sure you have a portable stove and fuel. Have a minimum of 2 weeks of food for every person in the house. That is about how long it will take to get emergency systems in place!

One real issue is post hurricane. In many places, the power may be out for weeks. Many people use generators to help them through. Portable generators need fuel and long-term storage of enough liquid fuel for 2 weeks can be a problem. They are loud!

Permanently installed natural gas or propane generators are much better. They have a big fuel source and they are not as noisy as portable units. They do require maintenance, so be prepared to change oil and spark plugs every 100 hours or every 4 days!

The best solution is a hybrid solar system combining solar panels, energy storage and a generator. It provides the power you need with minimal use of the generator. And the solar panels will save you money the rest of the time!

For help with hurricane preparedness, contact Tetra West Technology and ask about a Mi-Grid!

Solar Power System: How To Convert RV To Solar Power

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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.

Solar Power System: Everything you need to know to add solar to your Food Truck

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People living in the city are most likely to be familiar with the new trend of food trucks and their tasty fare, even though they have actually been around for years. With increasingly more people turning to the food truck industry for a cheap, quick meal and even at times a gourmet meal, patrons want a gourmet atmosphere. Emissions and noise from these gas guzzling generators can ruin that impression.

How can we now keep the power on our food trucks, while cutting the environmental impact?

The simple answer is to go solar. A lot of food truck vendors have discovered this, and are presently taking their local, sustainable and organic food job to the next level by using solar power. They aim to bring tasty, fresh, healthy and affordable food to the masses, and they are a more eco-friendly choice compared to several other fast food options.

Food trucks with solar power are presently taking a lead for several different reasons. A few include:

They are Cost-Saving

For many food truck operators solar is a cost-effective source of power. An average food truck owner operating on a traditional generator spends a minimum of $5 to $10 daily on fuel. There is also cost, labor and hassle in maintaining a generator. And the cost of replacement or repairing generators down the line can be costlier than installing solar panels. For a food truck operating 50 hours a week, the time for pay back can be as short as 9 months!

Traditional Food Trucks pollute the environment

The majority of food trucks operate on a diesel or gasoline generator that is specifically designed to run only a few hours. Operators tend to run them at a stretch for up to 14 hours, resulting in a high output of greenhouse-gas emissions, particulate matter, nitrous oxide and carbon monoxide. And the worst pollutant, is NOISE!

Considering the harmful effects, and the way solar power can offset operating costs, it is not difficult to see why solar food trucks are trending to solar. For more details on adding solar to food truck, contact [company name]

Off-Grid Solar Power System: Can I run my Air Conditioning too?

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Several individuals have always considered off the grid and air conditioning never to belong in the same sentence, suggesting that you cannot have air conditioning off the grid.

The general response has been NO. Reasonably priced Off- grid solar power cannot run Air Conditioning. They are not powerful enough or the cost of a system is too great.

Mi-Grid is different. Mi-Grid is a hybrid solar energy system, combining battery storage PV solar with a backup generator. Even the smallest Mi-Grid can operate an Air Conditioner. The inverters and generators are sized to be able to start and run appropriately sized units. A tiny Mi-250 can run any 15 amp 110VAC window unit or even a 15,000 BTU/hr RV air conditioner. A Mi-Grid 4000, can run two 5-ton Air Conditioners with properly installed soft-starters.

The BEST choice for Air Conditioning is always a Mini-Split or inverter drive air conditioner. They require little startup power and are extremely efficient, reducing the amount of energy used for cooling. For the smaller Mi-Grid units, choose a 110VAC unit. For the Mi-Grid 1000 and up, 220VAC units can used.

Standard window air conditioning units can also be a good choice for the smaller Mi-Grid systems since they are 110VAC. Usually these are installed in bedrooms or small areas. 110VAC units work great with an essential circuits Mi-Grid. Get the most efficient one you can afford. Again, a mini-split is always best for your “essential” room.

Large whole house type Air Conditioning units can work with larger Mi-Grid units, especially with the addition of a small A/C soft start unit. The normal problem with running Air Conditioners is the power needed for startup. It can be as much as 5 times the operating power. A properly installed soft starter limits the starting power to only 50% over running power. This means a smaller inverter or generator can startup a larger air conditioner. And as always, get the most efficient one as possible.

One type of air conditioner/heat pump works extremely well with whole house Mi-Grid systems. Geothermal heat-pumps circulate coolant into the earth where year-round temperatures are far more moderate. This allows the heat pump to work much more efficiently and use much less power. Some of them have SEER’s between 40 and 50!!!

Mi-Grid can also be setup to provide power to all your essential circuits and outlets. High power circuits, for example air conditioners, are setup to only run with the generator. This allows the comfort of air conditioning while minimizing generator operation.

One final note: Insulation and shade. The cheapest way to keep cool is to not get hot in the first place. A shaded home/RV will use much less power. The more insulation, and the higher R-value insulation, the less heating or cooling you will need. And finally, cook outside in the summer. The less heat you add, the less air conditioning you need. Solar doesn’t work in the shade, but potable solar panels or ground mount arrays, can be placed in the sun with your house or RV in the shade.

You don’t have to give up comfort off-grid. Mi-Grid provides the power for everything.