 Navajo Nation |
 Navajo Boundary Map |
It is located in between the northern region of Arizona and New Mexico and southeastern Utah. The Navajo Nation suffers from extreme poverty and with most household lacking access to basic plumbing, telephone service, and electricity. It is estimated that around 18,000 of the 48,000 households on Navajo lack access to electricity. Based on the 2010 Census of the Navajo Nation, 23% of total households has an income of less than $10,000, 25% has an income between $10,000 and $25,000, and 15.6% of the population is unemployed. In addition, the average household size in the Navajo Nation is nearly 4 person per household making it extremely difficult for most of the households to sustain a habitable environment with that income. This information presents the major issue with poverty and evidently lack of income to access stable and basic utilities needs, such as electricity. More demographic information can be found here.
Elephant & Eagle Energy was a non-profit that ‘seeks to improve the quality of life in developing communities by pioneering ventures that provide access to appropriate sustainable energy technologies (ASETs)’ they worked with a group of CU Boulder researchers who collected a lot of demographic and energy use data, and then distributed some PV power lights for residents in the Navajo Nation in 2010. Eagle Elephant Link.Their work primarily with solar lighting, and their data was helpful, but we decided to work with the appropriate technology class on water heating.
According to Elephant & Eagle, the main tasks electricity is used for in the Navajo Nation include lighting, cooking and water heating. Water heating in the Navajo Nation is majorly done by burning wood and gas, which have many negative impacts and risks on the environment and health. With small PV systems and simple resistive elements we could reduce the heath and fuel costs for these commodities. For PV systems, after the initial capital costs the fuel (sunlight) is free!
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The graph above shows that in the Navajo Nation a lot of the population is burning wood and using kerosene, or going without the electricity because of lack of connection to the grid.
The average household in the Navajo Nation is spending about $135.00 per month on wood as an energy source. Investing in solar could help them re-direct their money to more efficient ways for more, cleaner cost efficient sources. This graph shows the average amount spent per household per month on energy. About 16% of households have generators, and this graph shows they cost a lot. These costs are per household who have generators, the generators are mostly supplied by the NTUA (Navajo Tribal Utility) as an energy source for those who can afford it.Gas is gasoline for the generators.
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| In October 2010 These are the amounts Navajo Residents are spending for energy sources |
Dig Deep is currently providing solar electric systems as well as water heaters. The price for a water tank system that includes the “
purchase of a 1200 gal. cistern, pump, sink, plumbing, electrical, labor and shipping”, is currently $3100.00. The price for the solar system including the “purchase of a solar panel, battery, wiring, LED lights, charging ports, propane water heater, electrical, labor and shipping”, is $1400.00.
In this group, we are currently working towards providing cheap and sustainable access to electricity for most households in the Navajo Nation. One of the main reasons for the lack of access to electricity is the geographic isolation of individual households. This makes it too expensive to implement a modern electric grid system and extend power lines between each home over a vast empty area. The average cost of extending existing lines a single mile is about $50,000. A large-scale PV system is also expensive that only a few households can afford. In early 2010, the Navajo Tribal Utility Authority, NTUA, introduced a leasing program for a 2kW PV system to power lighting and small appliances needs that would cost an $85 initial fee and a fifteen-year lease of $95 per month. However, this program has received low participation with only a few hundreds of household on the leasing program. According to Michael Giberson, PHD from Texas Tech University,the calculated LCOE (levelized cost of electricity) for wind power is about $109/MWh not including indirect environmental costs. In 2010 a proposal by NTUA (Navajo Tribal Utility Authority) to build an 85Mw wind farm was approved by the president and Navajo Council. The proposal included about 300-500 temp jobs and 10 permanent jobs. The wind farm was never made as there as disagreement between the central Navajo government and local Cameron chapter in the area to be built. https://en.wikipedia.org/wiki/Navajo_Nation. Using some cost estimates from the Giberson Study above, and “Wind Energy in Indian Country: Turning to Wind for the Seventh Generation” below we calculated the LCOE for wind power. This number is much less then Giberson’s Calculation because I used land lease costs and business taxes for the Navajo nation specifically.
The Appropriate technology class is working on building a water tank to see if they can build a system that is less expensive then the ones being deployed by DigDeep. We were able to help provide guidance as well as go to the Student Experimental Farm to safely hook up the water heater resistive element with the solar panels.
For heating water:
30 gal of H2O * (8.345 lbs / 1 gal of H2O) = 250.2 lbs
250.2lbs * 100 °F = 25021.0 BTU
1 BTU = 0.000293 kWh
25021.0 BTU * (0.000293 kWh / 1 BTU) = 7.33 kWh
Resistive heating elements are rated to output 3.7 kW with 240 V from the panels. This means the resistance is about 15.6 ohms.
To heat water from 50 °F to 200 °F
7.33 kWh / 3.7 kW = 1.98 hrs
For full solar irradiation.
The rest of the time the power from the solar panels can be used to charge the battery, or power lights and charge phones.
In our solar system, we are using three 7 W 12 V LED strips, two 5 W 5 V charging ports and a 96 W 12 V water pump. Assume the three LED strips needs to be on for 6 hrs a night and the families will charge two phones per night. Phone chargers take approximately 2 hours to fully charge a phone. Families will only need to pump for a total of 1 hour per day.
7 W/Light * 3 Lights * 6 hrs = .126 kWh
5 W/Charger * 2 Chargers * 2 hrs = .002 kWh
96 W/Pump * 1 Pump * 1 hr = .096 kWh
Total Power = .224 kWh
Batteries are typically rated by Amp hours or AH = .224 kWh / 12 V = 18.6 AH per night.
The Schneider C40 charge controller and the 55 AH Duracell battery works for this system.
The circuit design consists of the solar panels, connecting to the resistive element and a thermostat button using 16 guage wire with the SunPower 425 W panels. This part of the circuit is to be hooked up to a charge controller that is also connected to a Lithium Ion battery. The battery will be used to run the water pump, as well as provide a ports for charging of cell phones and lights. The charge controller need to be able to efficiently transfer the 425 W from the solar panel at 73 V and 6 A to both the batteries and resistive element in heater. Therefore, we decided on the Schneider-Electric C40 Multifunction DC Controller connected in Diversion Control Mode, as shown in the figure below. Diversion Control Mode prioritizes charging the batteries over the heater, allowing the system to power other more important components, because we decided the water heater is not a necessities.
Diana Swanson, 2nd year Physics Major
Trung Nguyen, 4th year Electrical Engineering Major
Daniel Dich-Dang, 4th year Electrical Engineering Major
– The above table doesn’t show on my browser. Please figure out a way to present it so I can see it. Is there information explaining it?
I think it would be nice to calculate what it would cost to bring industrial grid to the families versus distributed generation with solar and/or wind. However, you can decide how to allocate your time on this project. I disagree with your statement below. Presently DigDeep (Please discuss this NGO and put a direct link to their webpage and the webpage for the appropriate technology group working on this) is building systems for these people that are really overpriced. It seems that at the present cost of the systems they are putting in, we could easily design an electrical system for them that would fill all their needs, but I could be wrong.
According to Michael Giberson, PHD from Texas Tech University,the calculated LCOE (levelized cost of electricity) for wind power is about $109/MWh
– = $0.11 / kWh… under what circumstances? Is this cost correct for this area? What are the energy storage implications? Would they try a DC grid? This may be a very large question, and well beyond the scope of the project. I encourage you to estimate the LCOE for the solar panel connected that you determine the power for that you will connect to your electrical system. You can do a simplified basic calculation and then add details as we know more.
not including indirect environmental costs. We are working on costs calculations for hooking up to the grid and solar panels to decided which is best.
– This is an important calculation. I’m sure you will find appropriate information online to support these calculations. You may need to find out where people live to make an estimation of what this will cost. You could start by asking if someone has done such a calculation. I would recommend asking George.
Please better describe the graph below. Is this the average cost a per family, per year? What portion of the people have generator? Is gas gasoline? Grid: how is this cost calculated? Is there some grid connection and they just divided this cost by the total number of people on the reservation?
This is an improvement. Thanks. Please provide schematic of what the electrical/water system will look like, and a wiring diagram.
Please calculate power needs, identify a battery and charge controller that will work for this and the LED lights. I presume you’ll use a 12 V DC system without an inverter… correct? Please develop this in the coming week.