Multiple ways of getting Net-0 energy building

No matter which green building evaluation we are using, LEED, green globe or LBC, energy consumption is one of the biggest concern. In fact, LBC requires net-0 energy building in its requirement. PV panel maybe the most available products to reach that point, however, its low efficiency and high cost encounters a lot of critics. Not to mention its CO2 emission in it's producing.

Truly, solar power is the only energy resource for the world, but there are multiply ways of storing this type of energy. Our nature world gives an perfect example about how to transfer energy and the idea is becoming realistic. For example, algae solar cells:

Algae is widely existed in nature. After direct or indirectly lighting, they will produce a product called SVO or straight vegetable oil which can be transfer into bio-diesel later. In this processing, it absorb CO2 and emit   O2. This is also the basic idea of algae solar cell. In the processing, only water and CO2 are needed. Algae is 3 times efficiency than PV products; And if treated correctly, we may use brown water instead of using portable water. Biomass left will total green.

The first Algae building is located in Germany.  "A 15-unit apartment building has been constructed in the German city of Hamburg that has 129 algae filled louvered tanks hanging over the exterior of the south-east and south-west sides of the building—making it the first in the world to be powered exclusively by algae. Designed by Arup, SSC Strategic Science Consultants and Splitterwerk Architects, and named the Bio Intelligent Quotient (BIQ) House, the building demonstrates the ability to use algae as a way to heat and cool large buildings."

Compare to traditional PV products, the system may have some short legs: 

1. it's not generating electrical but bio-diesel which is considered as a lower level of energy. There will be some energy lost if transferred into electrical power.

2. More complex system and cost more on maintenance.

3. Special environment control required. 

4. Not mature marketing yet

...

At least, it opens our minds on how to utilize solar energy besides PV technology.