China is getting Power from the World's largest floating solar farm



Recently, China has decided to become a leader in renewable energy.  China is one of the most polluted countries in the world and is trying to turn that around.

In May of 2017, the Chinese government announced the completion of a 40 Megawatt solar farm located in the Eastern Anhui region of China.

The farm sits atop of a flooded farm town.

The system was created by Sungrow Power Supply and sits on the water off the coast of an old coal mining town.

Because the system is sitting on top of water, it is actually more efficient and cost effective.  The water acts as a natural coolant, making the panels more efficient.

Other Solar Farms in China

On June 30th, 2016 a 50 Megawatt solar farm was completed in China, there’s a small twist.  Whereas most solar farms are made in straight rows, the solar farm is in the shape of a Panda.

The 248 Acre solar farm was constructed by China Merchants New Energy Group, one of China’s largest clean energy operators.

The system will eliminate over 2.47 million tons of CO2 over 25 years.


Mini-grids Could Bring 100 Million Africans Clean, Affordable Power


In Africa, over 600 million people live without access to electricity.  There is an ongoing debate on how to best implement power solutions for these people and new research by CrossBoundry shows that mini-grids could play an important role.

Different Methods Of Providing Power

When looking at the issue of how to provide power to people who don't have access, there are three primary methods: grid expansion, standalone home solar, and mini-grids.  All three have a role to play depending on the situation.

What is a mini-grid?

A mini-grid is a small scale grid that generates, stores, and transmits power.  They can serve isolated households and businesses that don't have access to central grids.

A mini-grid can be put together with any power generation technology, but things start to get interesting when the concept of a mini-grid incorporates solar.

A solar-powered mini-grid with battery backups allows rural communities to sustainable generate power regardless of location.

Who is the best candidate for a mini-grid?

A mini-grid isn't always the best means of providing power to people, but according to CrossBoundry, approximately 100 million people are perfect candidates for mini-grids in Africa.

CrossBoundry combined data from the World Bank and WorldPop to map the main grid and the distances of populations in relation to the grid.

According to GreenTech Media, "CrossBoundary started by combining the data on existing and planned high-voltage transmission lines from the World Bank with data on the population density of Africa by square kilometer from WorldPop. 

This allowed us to map out where each square kilometer of the population is relative to the high-voltage grid. These datasets paint a clear picture of the challenges for electrifying rural Africa. 

 image courtesy of Greentech Media

image courtesy of Greentech Media

First, Africa in parts is sparsely populated: Over 350 million people live in square kilometers that contain fewer than 100 people, equivalent to a family of five living on ten football fields of land. 

Second, people often live remote from infrastructure: 135 million people live more than 100 kilometers from existing and planned high-voltage lines."

The people who are best candidates for a mini-grid are those who live far from a central grid and live in places with high enough population density. 

How A Minimum Cost Was Estimated

CrossBoundry built cost estimates to achieve tipping points between mini-grids, main grid expansions, and home solar systems.  

They analyzed the costs of all three power generation methods to figure out a break-even distance where localized solutions become cheaper than grid extensions.

CrossBoundry found that "mini-grids are cheaper than grid extensions at an average tipping point of 25 kilometers from the high-voltage grids and less expensive than home solar at an average tipping point of 400 people per square kilometer."

How Much Would mini-grids Cost?

Upon finding the best candidates for mini-grids(100 million), 15 existing mini-grid projects costs were analyzed, and an estimate was created for providing 100 million people with mini-grids.

It is estimated that it would cost 11 billion USD to power 100 million people with solar powered mini-grids.


Many questions and hurdles still need to be assessed such as subsidies and private vs. public ownership mix.  Mini-grids though are the most economically viable method for providing power for 100 million people in Africa and needs to be taken seriously as donors and governments look into electrifying Africa.


Original Story at GreenTech Media

2 Home Batteries Competing with Tesla’s Powerwall II.

Home energy storage has been getting more and more attention since Tesla announced its Powerwall battery. While Tesla’s Powerwall put the spotlight on home energy storage, other companies have been offering similar solutions for some time. But are they any good? 

In this post, we will compare 2 competing batteries to the Tesla Powerwall II to find out if there are better home energy storage solutions.

How we will be comparing:

We will look at the 5 categories that we believe are the most important in a good home battery: Aesthetic, power capacity, adaptability, lifespan, and efficiency.

A rating will be given for each category based on a scale of 1 to 5 with 5 being the best.

Tesla Powerwall II

 photo courtesy of

photo courtesy of

Before we start exploring the three home batteries that are competing with Tesla’s Powerwall, let’s take a quick look at the Powerwall II.

The Powerwall II promises to make home energy storage affordable, scalable, and beautiful.

The Powerwall II as the name implies is the second generation of Tesla’s home battery.  The first thing that is notable about the Tesla Powerwall II is its design. 


The design is very minimalist, clean, and slim; simply put, it looks pretty amazing. The Powerwall II incorporates a more boxy design compared the original Powerwall that makes stacking batteries much more manageable.

The new design makes it easier to stack batteries on top of each other without taking up too much room thanks to the 5.5-inch profile.

 Photo courtesy of

Photo courtesy of

Powerwall II Capacity, Efficiency, and Scalability 

The Powerwall II is made from lithium NMC (Nickel-Manganese-Cobalt) and has a capacity of 13.5 kWh.  The lithium NMC battery cells were developed in collaboration with Panasonic and are similar to the cells used in Tesla's electric vehicles.

The Powerwall II has a 90% round-trip efficiency and a 100% depth of discharge.  The roundtrip efficiency means that for every watt of energy put into the battery, 90% can be output to power your home.  Engineers typically want to see over 80% roundtrip efficiency.  The higher the roundtrip efficiency the better.

The Powerwall II can be stacked to achieve higher capacities.  It is possible to stack up to 10 Powerwall II's, making this one of the most scalable residential and small commercial batteries on the market.  A Powerwall II system can store up to 135 kWh.

Powerwall II Ratings

  • Aesthetic: 5/5
  • Power Capacity: 5/5
  • Adaptability: 5/5
  • Lifespan: 4.5/5
  • Technology: 4.5/5



LG has been making lithium-ion batteries for over 8 years.  They started producing batteries in 2010 and have seen a lot of success.  Their newest battery the RESU Is their first battery that is looking to go toe to toe with the Teslas Powerwall II.

The new range of RESU batteries from LG includes RESU3.3, RESU6.5 and RESU10 units with an option to combine different units using a new adapter for up to 19.6kWh of total storage.


The LG RESU batteries have taken a much different approach than Tesla with their design.  The design of the LG RESU batteries resembles a heat sync or a radiator.  The outside surface of the LG battery has a striated front panel and rounded corners. 

The LG RESU comes in a two-tone design of gray and black.

LG RESU Capacity, Efficiency, and Scalability

Similar to the Powerwall II, the LG RESU is made from lithium NMC (Nickel-Manganese-Cobalt) and has a maximum capacity of 9.8 kWh for the highest capacity unit.  The battery is also IP55 weather rated and has a 10 year warranty.

The LG RESU has a 95% round-trip efficiency(claimed) and an 80% depth of discharge. 

Unlike the Powerwall II, the LG RESU isn't as flexible when it comes to stacking.  The LG RESU does have a special configuration that makes it possible to build a 19.8 kWh battery but that is where it maxes out.  Although not highly scalable, the LG RESU is highly flexible.  It works with many inverters and solar systems right out of the box.

Powerwall II Ratings

  • Aesthetic: 3.5/5
  • Power Capacity: 4/5
  • Adaptability: 4/5
  • Lifespan: 4/5
  • Technology: 4.5/5

Sonnen Eco

 photo courtesy of  Sonnen

photo courtesy of Sonnen

Sonnen was founded in 2010 has is on their 8th generation battery.  From the beginning, Sonnen has been focusing on making incredible safe, and long lasting battery storage solutions.  Their newest battery, the Sonnen Eco puts up a serious fight against the Tesla Powerwall II

The Sonnen Eco batter is available in varying sized from 4 kWh to 16 kWh.  You can scale the battery in increments of 2 kWh.


The Sonnen Eco battery has a simple design that helps it blend into any home.  The Sonnen Eco is one of the few batteries that can compare to the Powerwall II in terms of design.  It has a simple box shape that changes depending on the battery capacity.

The Sonnen battery does stick out more than the Tesla battery with a profile of 14 inches.  

 photo courtesy of  Sonnen

photo courtesy of Sonnen

LG RESU Capacity, Efficiency, and Scalability

One of the biggest advantages to the Sonnen battery is its construction.  The Sonnen Eco is made form a lithium-iron phosphate (LiFePO4) battery technology, one of the most reliable, safe and long-lasting lithium battery technologies currently available.

 LiFePO4 is great for stationary storage systems due to its uniquely high chemical stability which results in reliability, durability and long battery lifespan.

Sonnen's batteries are Guaranteed to last  10,000 cycles or 10 years.

The Sonnen Eco has a 93% round-trip efficiency(claimed) and an 100% depth of discharge. 

Unlike the Powerwall II, The Sonnen, like the LG  isn't as flexible when it comes to stacking.  Sonnen does offer different sizes of battery but you can't stack them on top of each other like you can with the Powerwall II.

Powerwall II Ratings

  • Aesthetic: 4.5/5
  • Power Capacity: 5/5
  • Adaptability: 4.5/5
  • Lifespan: 5/5
  • Technology: 5/5


With the introduction of the original Powerwall, Tesla helped put a lot of attention on the energy storage market.  There are now competitors that make good batteries that can compete with the Powerwall II.

The Tesla Powerwall II is still the best battery on the market when available but the Sonnen Eco is an incredible alternative that delivers great performance and aesthetic.