Sustainable Development and Energy

Solar Energy

conversion of sunlight into usable energy forms

Solar photovoltaics (PV) and solar thermal electricity

estaSun radiation arrives outside the Earth with a specific spectral distribution, which is modified throughout the atmosphere until reaching the Earth’s surface.

Geographic latitude

Time of day

Year

The amount of solar energy available on a given location of the earth differs depending on the:

Solar radiation components

Direct radiation

Diffuse radiation

Direct radiation

radiation from the sun that reaches the Earth without scattering

Direct radiation

it can be concentrated using technological devices

Diffuse radiation

radiation that is scattered by the atmosphere and clouds

Established Solar Technologies

Solar PV

Solar Thermal

Solar PV

Directly converts solar energy to electricity

Solar PV

Absorbs 80% incident solar radiation but convert only small portion to electricity

Solar PV

Release excess heat during the operation

Solar Thermal

Harnessing solar energy for thermal applications – domestics, industries, hotels, hostpitals, leisure, etc.,

Solar Thermal

Use thermal energy for space heating, fluid and generate electricity

Solar Thermal

Has been accepted worldwide as solar thermal power

Solar Thermal Collector

converts solar radiation into useful heat and its performance depends both on optical and thermal features.

Different Solar Thermal Technologies

Parabolic Trough Solar Thermal System

Central Tower Solar Thermal System

Linear Fresnel Solar Thermal System

Parabolic Dish Solar Thermal System

Flat plate solar collectors

Parabolic Trough Solar Thermal System

System where the troughs concentrate sunlight onto a receiver tube that is positioned along the focal line of the trough.

Example: SEGS in California, with 936,384 mirrors

Central Tower Solar Thermal System

system takes advantage of numerous heliostats to reflect sunlight onto the surface of the high-temperature heat absorber on the top of the center tower.

Example: Ivanpah 440 MW Power Facility, California, 214,000 heliostats

Linear Fresnel Solar Thermal System

one-axis solar tracking device, with the parola divided into many small nearly flat mirrors with independent movement, simultaneously focusing the linear absorber located in optical focus.

Example :Murcia, Spain with 100MW/km2 land use

Parabolic Dish Solar Thermal System

heliostats with sunlight focused on the engine with a cavity receiver on the focal point. One of the most efficient solar electric technologies.

Example: Arizona, US

Flat plate solar collectors

mostly used in heating water for showers.

Example: small-scale than other examples, used in heating water in swimming pools and showers

Heliostats

two-axis tracking mirrors which concentrate solar radiation maintaining the reflected image at fixed position over the course of the day.

Solar Collector

Solar photovoltaics Advantage

Module manufacturing is being done in large plants, which allows for economies of scale, and it can be deployed in very small quantities at a time

Solar photovoltaics Disdvantage

As PV generates power from sunlight, power output is limited to times when the sun is shining. However, a number of options (demand response, flexible generation, grid infrastructure, storage) exist to cost-effectively deal with this challenge.

Biomass Energy

burning of wood, bark, branches, starchy roots, manure and other plant and animal materials to produce energy

Example: San Carlos Biopower Inc. in Negros Occidental

Biomass Energy Conversion Process

Hydropower

falling water produces energy which is harnessed as a valuable contribution to total energy supply.

Example: Maria Cristina Falls and Agus VI Hydroelectric Plant, supplying 200 MW of electricity

Less destructive alternatives to dams

low-head hydropower technologies

Wind

Wind energy comes from capturing kinetic energy using turbines to generate electricity, and can be onshore or offshore.

Example: Pililla Win Farm in Rizal, supplying 54 MW to Meralco

Energy Mix

refers to how final energy consumption in a given geographical region breaks down by primary energy source

PH Energy MIx

Renewable Energy in the Philippines

Hydropower

Geothermal

Biomass

Solar, wind, ocean

Biofuels