mercredi 29 novembre 2017

Controversy over alternative energy

Biomass power renewable energy

Biomass in ecology

  The definition of biomass in ecology is the mass of living organisms in a given area or ecosystem at a given time. Biomass can refer to one or more species biomass which is the weight of one species in the community or to the community biomass which is the mass of all the species in the community. Biomass can include plants (phytomass) and biomass (zoomass), and in our present case, it's the weight mass of organically bound carbon number in tonne present who will be considered for its energy potential.

It is estimated that:
  • the total live biomass on Earth apart from bacteria is about 560 billion tons of carbon 
  •  The world bacterial biomass was calculated to be 350-550 billion of tons of carbon, equal to 60%-100% of carbon in plants.
  • 95% of the biomass is in the continents
  • only 5-10 billion of tons of carbon are found in the oceans
  • on land, there's 1000 times more plant biomass than animal biomass 
  • 18% of all this plant biomass is eaten by animals on land
  • in the ocean, there's 30 times more animal biomass than plant biomass
  • most plant biomass on the ocean is eaten by animal's biomass 
  • the Earth's total annual production of the biomass it is estimated to be 100 billion tons of carbon a year. 


  Biomass power is the energy derived from vegetable or animal matter which can be harnessed to produce electricity. In the field of bio-energy, biomass is the part of it still usable as a source of energy; either directly by combustion or indirectly after methanation (biogas, or its uncluttered version bio-methane).     
  Wood is still the largest biomass energy source today. Natural wood logs are used on a large scale, this includes also branches, forest residues, dead trees, municipal wastes, etc... The largest source of energy from wood is pulping liquor or "black liquor" a waste product from processes of pulp, paper, and paperboard industry. It's used in the pulp mill's industry. They use recovery boilers to burn the black liquor to create and produce steam. Wood is considered an alternative energy source because it pollutes less than fossil fuel, and it is being considered a renewable energy source because plants crop can be replaced with new growth.
  Pellet fuels are made from organic compressed matter or biomass. Pellets are made from one of any five general categories of biomass: industrial waste and co-products, food wastes, agricultural residues, energy crops, and virgin lumber. Wood pellets are the most common fuel pellets, and they're made from compacted sawdust and related industrial wastes.

  Many crops are of interest for their ability to provide high yields of biomass, like sugarcane. Bagasse, its residue is produced in great quantities. The production of bagasse is evaluated at 250 million tons a year, it can serve to feed animals. It has a poor nutritive value and can be fermented by white-rot fungi to produce enriched animal feed. Bagasse and other sources such as cornstarch who are rich in sugar can be fermented to produce first-generation biofuels. Bio-ethanol is an alcohol that can serve directly in a fuel cell to produce electricity or as an additive to gasoline. But utilizing food-based resources for fuel production can only aggravate the food shortage problem. Second-generation biofuels, on the other hand, utilize non-food biomass products such as municipal and agriculture wastes. Despite being the favored alternative of production of bio-fuel,
second-generation biofuels isn't achieved yet due to technological issues. Energy derived from biomass is projected to be the largest non-hydroelectric renewable source of electricity in the U.S. between 2000 and 2020.

  Some biomass products like ethanol and wood have a poor calorific value, compared to the energy released by burning 1 tonne of oil equivalent 0,3215 (toe).
The tonne of oil equivalent (toe) is a unit of energy, it's approximately 42 gigajoules or 11 600 kWh. And a tonne of crude oil is approximately 7,3 barrels. 


The calorific value in comparison with crude oil: 

  • 2,2 tonnes of wood = 1 toe 
  • 1,5 tonnes of high-quality coal = 1 toe
  • 1 ton of uranium (in light water reactor) = 10000-16000 toe
  • 1100 m³ of natural gas = 1 toe 
  • 1 tonne of diesel = 1,01 toe
  • 1 tonne of bio-ethanol = 0,64 toe

  Electricity production comparison value:

  • geothermal electricity :              1MWh = 0,860 toe
  • nuclear electricity :                    1MWh = 0,261 toe
  • fossil or renewable electricity :    1MWh = 0,086 toe
  • Natural gas electricity :              1MWh = 0,077 toe

dimanche 26 novembre 2017

Solar power technologies pros and cons

Controversy over alternative energy  

The costs of solar energy(part 4)

  Photo-voltaic solar panels system on your households who produce electricity are photo-voltaic cells, connected together to a solar module, who transform solar radiation into electricity. Generally, several modules are grouped together to form an installation. They are usually installed on the roof so that the slope is sufficient for the snow to slide on the walls of glass and to better capture the brightness of the Sun.
   DC power generated from solar radiation is used to power a device or recharge a battery. The power must first go through an inverter before being converted to 110V and routed to the house. Generally, people are connected to the electricity grid and work with a battery, because they can get supplies from the electricity company if their needs are not met by solar energy. Off-network users use batteries that provide power, regardless of brightness and variations in demand. In eastern Northern-America, these batteries provide a stable diet during the shorter days of autumn and early winter.
   All that consumes electricity can be powered by photo-voltaic panels, namely lighting, appliances, computers, small electrical appliances. However, for anything that generates heat, such as heating the house and water, it is better to use another technology: solar thermal energy. Indeed, it is more efficient and less expensive to generate heat with this technology.
   By cons, the costs are very important if you have the idea of converting your single family house into solar energy. But the investment can be worth the cost, even in Quebec. In Quebec, it is estimated that electricity produced with photo- voltaic panels cost six times more than the price of residential electricity. A kWh produced with solar photo voltaic energy costs about $0.42 compared to the $0.07 per kWh requested by Hydro-Quebec.
   Even if Hydro-Quebec does not go to the residence or if the cost of connection to the network exceeds $15,000 to $20,000, it is advantageous to install solar panels. It all depends also on where you live, how much you pay for your electricity in kWh in your state or province. How much you spend on electricity each month and how much you think you'll be saving with your solar panels system each year...
   For example, the average annual electricity use for Canadian and U.S. households is 11,000-kilowatt hours (kWh). Multiply that by the national average electricity rate as of September 2016 ($0.1287 per kWh) and you'll find that the typical American family is spending over $1,400 a year on electricity alone.
   Then, you'll have to consider also the volatile nature of electricity prices, determine what utility rates will be in years to come. When you compare the cost of utility electricity with solar home, you should keep in mind that you can expect electricity rates to increase annually. Over the past decade, national electricity costs increased by 2.2% per year.

Average solar panels installation:

  • System size: 5 kilowatts (the national average)
  • Electricity demand: 11,000kilowatts-hour per year (national average)
  • Utility rate inflation: 2,2%
  • Percent needs meeting by solar panels: 84%
  • Electricity rate
  • Ownership of the solar panels is assumed

The annual solar energy production of solar systems:

  • 3kW                    4,260 kWh
  • 4kW                    5,680 kWh
  • 5kW                    7,100 kWh
  • 7kW                    9,949 kWh
  • 8kW                   11,360 kWh
  • 10kW                 14,200 kWh
  • 12kW                 17,040 kWh
  • 15kW                 21,300 kWh

Cost of electricity in kilowatt per hour:

  • Quebec:           7 cents kWh
  • Toronto:         14 cents kWh
  • Moncton:        12 cents kWh
  • Chicago:         17 cents kWh
  • New-York:      29 cents kWh
  • Boston:           30 cents kWh

So, if you live in a place like the province of Quebec, it'll take you as 4 times longer to get your return of investment on your solar panels system compare with how much you pay for your electricity bills in Boston, Massachusetts or in New-York.

Examples of costs for equipment (installation included)

Prices are approximate

Example 1

Medium sized family households
Not connected to the utility grid's

24 panels = 2,880 watts / $15,000
12 batteries / $6,000
Other equipment / $7,000
Total: $28,000

Example 2

Chalet, weekend use
Not connected to the utility grid's

8 panels = 960 watts / $5,000
6 batteries / $3,000
Other equipment / $4,000
Total: $12,000

Example 3

Small hunting & fishing hut, RV
Not connected to the utility grid's

2 panels = 240 watts / $1,250
2 batteries of 12 volts / $400
Other equipment / $550
Total: $2,200

Solar power technologies pros and cons

Need to structure solar energy technologies. (Photo credit: Wikipedia)

Solar power technologies pros and cons

Controversy over alternative energy  (part 3)

Solar and renewable energy, Chinese business

  The Sun is at the origin of most of all the energy sources on Earth except for nuclear energy and deep geothermal energy. Solar energy comes from nuclear fusion at the centre of the Sun, the energy spreads in the Solar system and the Universe in the form of an electromagnetic radiation, photons, and infrared radiation. A fraction of the electromagnetic energy from the Sun is coming true the atmosphere, which absorb a part of it and reach the surface of the Earth.
  The conversion of light in electricity called photo-voltaic effect was discovered by the French physicist Edmond Becquerel in 1839, but we'll have to wait a hundred years before scientists deepen and exploit this phenomenon of physics. It's the space exploration and NASA that will really make solar energy progress. The space industry will invest a lot of funds in the development of solar panels. Solar panels are the only non-nuclear way of powering satellites with energy, moreover, solar energy is a constant source of energy in orbit. 

  While President Trump promises to put American coal miners back to work, China is moving the opposite direction. China's betting big on renewable energy. It commits in January to invest $367 billion in renewable power generation: solar, wind, hydro and nuclear by 2020. The investment will create 10 million jobs in the sector. Beijing is investing hundreds of billions of dollars and creating millions of jobs in clean power. China currently boasts 3,5 million jobs in clean energy, by far the most in the world, according to the International Renewable Energy Agency. 
  China has built vast solar and wind farms, helping fuel the growth of major industries that sell their products around the world. It's 2,5 million people working in the solar power sector alone in China, compared with 260,000 people in the U.S. China produce 63% of the world production of solar photostatic (PV) and it has emerged as the world's largest manufacturer of 2015. Solar power in the People's Republic of China is one of the biggest industries in China. Chinese solar panels production reportedly quadrupled between 2009 and 2011 to surpass the entire global demand. The flood of Chinese panels was one of the reasons why world prize crashed by 80% between 2008 and 2013. As a result, The United States and EU accused China of dumping its solar panels in Europe at below the cost-prizes. 
  The country has become a major manufacturer and exporter of renewable energy technology, supplying two-thirds of the world's solar panels. China has also a strong grip on wind power. It produces nearly half of the world's wind turbines at a rate of about two every hour.
There are two large families of short-cycle solar energy to distinguish:
  • thermal solar energy, the use of radiation heat of the Sun and also CSP concentrating solar power system by using mirrors or lenses of a large area into small a small one
  • PV photo-voltaic energy, the use of radiation itself to produce electricity
 Solar energy received at a point of the globe depends on:
  • solar energy sent by the Sun and arriving in the immediate vicinity of the Earth (decadal, seasonal, and punctual fluctuations of the Sun)
  • cloudiness (clouds, fog, etc.) which varies enormously from one place to another
  • latitude, season, and time, which affect the height of the Sun and therefore on the energy received per unit area, as well as on cloudiness as a function of the local climate
 As a renewable energy source, the part of the world finale consumption's production of electricity of photo-voltaic solar panels was estimated to be 1,2% in 2015. Solar energy from solar panels has multiples advantages: it's a renewable and inexhaustible energy source because it's coming from the rays of the Sun. It's a clean energy source because its respects nature and the environment. It's reliable, installation is easy to use, the cost of operation is low and maintenance is reduced.