Posts tagged with "renewable energy"

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!

Mi-Grid vs. the Powerwall

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We’ve had a lot of requests to layout the difference between a Mi-Grid system and a Powerwall. So, here goes!

First, let’s define a “Powerwall”. It is a Lithium-ion battery pack. It is not a complete power system. Implementing it requires a StorEdge inverter from Solar Edge. If you have solar, you also need a SolarEdge grid tied inverter and all of the required safety systems, breakers, disconnects, to properly implement. The “cost” most people associate with the Powerwall is only the price of the battery pack.

The SolarEdge+Powerwall system is a Grid-Tied solution. It cannot be used for off-grid. The Powerwall+SolarStor is designed to supply short term power from its battery pack for short (hours) service interruptions. If solar is present, it can store and disperse energy from the solar panels after sunset. However, the cost to store and retrieve the energy may be above the cost to sell to the network, even without net-metering.

http://www.solaredge.com/sites/default/files/se_storedge_inverter_datasheet_eng.pdf

Mi-Grid was originally designed as an Off-Grid system, specifically for the Off-Shore oil industry. It is designed to allow long term or permanent power with or without a utility connection. Mi-Grid’s Energy Management System (EMS) can take in multiple AC and DC sources, supply power and recharge batteries, all at the same time. It is also rugged and can be implemented outdoors.

Mi-Grid is “Agnostic” with respect to AC power, type of and manufacturer of solar panels, battery systems, as long as they meet the specified voltage ranges. Mi-Grid even has modules which can make use of “dirty” unstable utility power and turn it into “clean” pure sine-wave power.

Mi-Grid can be connected to a generator, allowing off-grid or utility down operation. The generator is only used off-grid or if the utility is down. The Generator recharges the batteries on cloudy or high power usage days, then shuts down. Even when operating with the generator, the solar array can assist recharging the batteries and supplying power. If the batteries become full, the EMS will modulate the array to match the power required,

The StorEdge-Powerwall system cannot implement a generator safely, unless the entire Solar/PowerWall/Stor-Edge system is bypassed. It uses a grid-tied inverter which cannot modulate the solar array output. Once the batteries are full, if the solar array output exceeds the user’s needs, it would send power to the generator, probably damaging it, potentially catastrophically.

Cost: It depends. Don’t you hate it when people say that? Mi-Grid comes with a generator and many more AC and DC inputs. If you eliminate the generator, you can compare the costs of the systems. The most fair comparison would be a Mi-Grid 1000 or Mi-Grid 2000 setup in essential circuits configuration. A Mi-Grid 1000 costs around $28,000 installed with 4.7kW solar and a 10kW generator. A Mi-Grid 2000 costs around $47,000 installed with 9.4kW solar and a 16kW Generator. Depending on location and codes, these prices can vary. For a “fair” comparison, you would need to implement 2 Powerwalls with any StorEdge System. You also need to include a SolarEdge 5 or 8kW grid-tied inverter and Optimizers at each panel.

Capability Comparison

	Mi-Grid 1000	Mi-Grid 2000	SE5000+PW	SE6000+PW
Max AC Power	4000	8000	5000	6000	Watts
Max AC Surge	8000	16000	7300	7300	Watts
Maximum Battery Output	4000	8000	1xPW=3300, 2xPW=6600		Watts
Energy Storage	19.2	38.4	1xPW=6.8, 2xPW=12.8		kWh
Energy Storage Usable	9.6-15.4	19.2-30.8	1xPW=6.8, 2xPW=12.8		kWh
Noise	<30dB	<30dB	1xPW=56dB, 2xPW=61dB		dB
Generator for contingencies	Yes	Yes	No	No
Grid-Tied	Yes	Yes	Yes	Yes
Off-Grid	Yes	Yes	No	No
Sell Excess Power	Yes	Yes	Yes	Yes
Run Whole House Air Conditioner	No	Yes	No	Maybe
Battery Life	3000 or 1800 Cycles, 50%/80% DOD respectively		1000@20% capacity loss 3000@60% capacity loss
Outdoor Rating	NEMA 4/IP66		StorEdge IP65, PW IP10

Getting ready for a Hurricane – from Mi-Grid

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!

El Nino means more Hurricanes

Get Ready For Hurricane Season: Investing In A Good Generator

Investing in Backup Power

A generator can be a good investment for backup power. They typically only need small capital investments, but operating a generator is not inexpensive. Generators use fuel, and they also require maintenance. Generators also have a finite life.

Different Types of Generators

Generators come in a few flavors. Small portable, permanent backup and prime power.
Prime power means the generator is rated to run all the time. They are the most expensive. If you need permanent off-grid power, these are the generators. They also last the longest. It is not unusual for these to run for 90 days between shutdowns.

Portable generators are the least expensive, but they require liquid fuel, typically gasoline. You will need to place these units well away from your house but still have long extension cords. And you will need these extension cords to run any electric devices in your house. Portable units are usually loud and not designed to be run for long periods. They need maintenance about every 50 hours.
Permanent automatic backup generators usually are connected to your natural gas supply or propane tank. An automatic transfer switch is connected to the electric supply. When it senses a loss of utility power, it will disconnect the utility power and start the generator. Power is usually back on in 30 seconds to 2 minutes. Small units provide power to essential parts of your house. Large units can run your entire house including air conditioning.

Installing Your Generator

Tetra West Power sells and installs automatic backup generators. We also build hybrid solar energy systems. Every backup generator we sell can be the base for a future hybrid energy system. Don’t lose power this hurricane season and install a backup generator today.