Title: Photosynthetic efficiency
Content:  of the light is in the photosynthetically active wavelength range, the theoretical maximum efficiency of solar energy conversion is approximately 11%. In actuality, however, plants do not absorb all incoming sunlight (due to reflection, respiration requirements of photosynthesis and the need for optimal solar radiation levels) and do not convert all harvested energy into biomass, which results in a maximum overall photosynthetic efficiency of 3 to 6% of total solar radiation. If photosynthesis is inefficient, excess light energy must be dissipated to avoid damaging the photosynthetic apparatus. Energy can be dissipated as heat (non-photochemical quenching), or emitted as chlorophyll fluorescence.
Title: Photosynthesis
Content:  Plants usually convert light into chemical energy with a photosynthetic efficiency of 3–6%. Absorbed light that is unconverted is dissipated primarily as heat, with a small fraction (1–2%) re-emitted as chlorophyll fluorescence at longer (redder) wavelengths. This fact allows measurement of the light reaction of photosynthesis by using chlorophyll fluorometers. Actual plants' photosynthetic efficiency varies with the frequency of the light being converted, light intensity, temperature and proportion of carbon dioxide in the atmosphere, and can vary from 0.1% to 8%. By comparison, solar panels convert light into electric energy at an efficiency of approximately 6–20% for mass-produced panels, and above 40% in laboratory devices. 
Title: Ecological pyramid
Content:  of the pyramid use solar radiation to power photosynthesis which produces food. However most wavelengths in solar radiation cannot be used for photosynthesis, so they are reflected back into space or absorbed elsewhere and converted to heat. Only 1 to 2 percent of the energy from the sun is absorbed by photosynthetic processes and converted into food. When energy is transferred to higher trophic levels, on average only about 10% is used at each level to build biomass, becoming stored energy. The rest goes to metabolic processes such as growth, respiration, and reproduction. Advantages of the pyramid of energy as a representation: Disadvantages of the pyramid of energy as a representation:
Title: Biological thermodynamics
Content:  The sun is the primary source of energy for living organisms. Some living organisms like plants need sunlight directly while other organisms like humans can acquire energy from the sun indirectly. There is however evidence that some bacteria can thrive in harsh environments like Antarctica as evidence by the blue-green algae beneath thick layers of ice in the lakes. No matter what the type of living species, all living organisms must capture, transduce, store, and use energy to live. The relationship between the energy of the incoming sunlight and its wavelength λ or frequency ν is given by  where h is the Planck constant (6.63x10−34Js) and c is the speed of light (2.998x108 m/s). Plants trap this energy from the sunlight and undergo photosynthesis, effectively converting solar energy into chemical energy. To transfer the energy once again, animals will feed on plants and use the energy of digested plant materials to create biological macromolecules.
Title: Metabolism
Content:  The energy in sunlight is captured by plants, cyanobacteria, purple bacteria, green sulfur bacteria and some protists. This process is often coupled to the conversion of carbon dioxide into organic compounds, as part of photosynthesis, which is discussed below. The energy capture and carbon fixation systems can, however, operate separately in prokaryotes, as purple bacteria and green sulfur bacteria can use sunlight as a source of energy, while switching between carbon fixation and the fermentation of organic compounds. In many organisms, the capture of solar energy is similar in principle to oxidative phosphorylation, as it involves the storage of energy as a proton concentration gradient. This proton motive force then drives ATP synthesis The electrons needed to drive this electron transport chain come from light-gathering proteins 
Title: Light harvesting materials
Content:  Photosynthetic biological systems utilize sunlight, an abundant and ubiquitous energy source, as metabolic fuel. The highest efficiency for the conversion of energy from the sun into biomass by plants is around 4.6% at 30 °C and 380 ppm of atmospheric CO2 for carbon fixation during  photosynthesis. Natural light harvesting complexes have molecular machinery that make possible the conversion of sunlight into chemical energy with almost 100% quantum efficiency. The ability of living organisms to harvest solar energy and achieve quantum efficiency near unity is due to the culmination of ~3.5 billion years of evolution. This efficiency is achieved in plants with a 
Title: Photosynthetic efficiency
Content:  ; 53% (in the 400–700 nm range) → 30% of photons are lost due to incomplete absorption, leaving ; 37% (absorbed photon energy) → 24% is lost due to wavelength-mismatch degradation to 700 nm energy, leaving ; 28.2% (sunlight energy collected by chlorophyll) → 68% is lost in conversion of ATP and NADPH to d-glucose, leaving ; 9% (collected as sugar) → 35–40% of sugar is recycled/consumed by the leaf in dark and photo-respiration, leaving ; 5.4% net leaf efficiency. Quoted values sunlight-to-biomass efficiency The following is a breakdown of the energetics of the photosynthesis process from Photosynthesis by Hall and Rao: Starting with the solar spectrum 
Title: Ecological efficiency
Content:  When organisms are consumed, approximately 10% of the energy in the food is fixed into their flesh and is available for next trophic level (carnivores or omnivores). When a carnivore or an omnivore in turn consumes that animal, only about 10% of energy is fixed in its flesh for the higher level. For example, the Sun releases 10,000 J of energy, then plants take only 100 J of energy from sunlight (exception- Only 1% of energy is taken up by plants from sun); thereafter, a deer would take 10 J (10% of energy) from the plant. A wolf eating the deer would only take 1 J (10% of energy from deer). A human eating the wolf would take 0.1J (10% of energy from wolf), etc. The ten percent law provides a basic understanding on the cycling of food chains. Furthermore, the ten percent law shows the inefficiency of energy capture at each successive trophic level. The rational conclusion is that energy efficiency is best preserved by sourcing food as close to the initial energy source as possible.
Title: Plant
Content:  Plants photosynthesize, which means that they manufacture their own food molecules using energy obtained from light. The primary mechanism plants have for capturing light energy is the pigment chlorophyll. All green plants contain two forms of chlorophyll, chlorophyll a and chlorophyll b. The latter of these pigments is not found in red or brown algae. The simple equation of photosynthesis is as follows: 
Title: Photosynthetic efficiency
Content:  this 0.3% number is something of a lower bound. Contrast this with a typical photovoltaic installation, which would produce an average of roughly 22 W/m2 (roughly 10% of the average insolation), throughout the year. Furthermore, the photovoltaic panels would produce electricity, which is a high-quality form of energy, whereas converting the biodiesel into mechanical energy entails the loss of a large portion of the energy. On the other hand, a liquid fuel is much more convenient for a vehicle than electricity, which has to be stored in heavy, expensive batteries. Most crop plants store ~0.25% to 0.5% of the sunlight in the product (corn 

Question: what percentage of sunlight is captured by plants to convert it into food energy?
Answer: 45%.
3 to 6%.