ETC 288 Alt Energy ETC 288 Alternative Energy

ETC 288 Alt Energy ETC 288 Alternative Energy Class 4 Saturday 2/25 9: 00 AM - noon Hydro Power

Class Notes • Mid Term Now Online at: http: //hss-1. us/sunyit/etc 288 -sunyit. htm – – Mandatory for ETC 288 Due 9 AM Mar 17 You may type in answers on word doc. Return Take Home Mid Term to instructor no later than 9 AM on March 17, 2012. – Options: By 9 AM on March 17, you must • (1) bring exam to class OR • (2) e-mail exam to instructor OR • (3) put exam in mail drop box – put in the large envelope, labeled Dr. Van Knowe, at Dr. Benincasa's Kunsela C 235 office – In class portion will be at end of class on Mar 17 • Closed book 5 questions • Week 5 (March 3 rd moved to Wed Feb 29 6: 15 PM) – Need to work out attendance issues in advance.

Hydro Energy Basics ETC 288 Alt Energy • Hydro power also called hydraulic power or water power - is power derived from force or energy of moving water, which may be harnessed for useful purposes • There energy available because of motion can be divided into two parts: – Kinetic energy available due to g from a drop of h over a dam (acceleration): P = hrgk – Kinetic energy available because of the horizontal stream flow r (momentum) 1/2ρAv 3

History ETC 288 Alt Energy • Hydropower historically used for – irrigation - water moved by power of water • irrigation used since 6 th millennium BC. • Ex: Turpan water system in ancient China - network of wells connected by underground channels - still in use – Operation of various machines - watermills, textile machines, sawmills, clocks, dock cranes, trompes • Water clocks used since early 2 nd millennium BC • trompes - water-powered compressor ( more on trompes later) – Location of population centers greatly influenced by availability of water and water power – World's First Hydroelectric Power Plant Began Operation September 30, 1882 Fox River Appleton, Wisconsin

Hydraulic Power Networks • Pipes carrying pressurized liquid to transmit mechanical power from power source, such as a pump, to end users • Extensive in 1870 s-1920 s in United Kingdom, Switzerland Ex- London Hydraulic Power Company – Pressure maintained at 800 psi (about 5. 5 MPa, or 54 bar) by five hydraulic power stations, driven by coal-fired steam engines. – At peak, network 180 miles (290 km) of pipes – Total power output about 7000 horsepower (5 MW) • • Hydraulic power networks- No longer in use; modern hydraulic equipment has a pump built into the machine ETC 288 Alt Energy • Ex. 1886 - new hydraulic turbines - built up excessive pressure after city’s craftsmen had closed valves in their workshops & gone home • Engineer created temporary outlet - a 30 m "fountain" to release pressure while reservoir system developed • Fountain became unnecessary - but Geneva wanted to keep asr tourist attraction • Today - 459 ft, 132 gallons/ sec at about 200 kph. Jet d’Eau, Geneva, Switzerland

Hydraulic Power Networks • Pipes carrying pressurized liquid to transmit mechanical power from power source, such as a pump, to end users • Extensive in 1870 s-1920 s in United Kingdom, Switzerland Ex- London Hydraulic Power Company – Pressure maintained at 800 psi (about 5. 5 MPa, or 54 bar) by five hydraulic power stations, driven by coal-fired steam engines. – At peak, network 180 miles (290 km) of pipes – Total power output about 7000 horsepower (5 MW) • • ETC 288 Alt Energy Hydraulic power networks- No longer in use; modern hydraulic equipment has a pump built into the machine Jet d’Eau, Geneva, Switzerland

Trompe

Hydroelectricity ETC 288 Alt Energy • Electricity generated by hydropower • Production of electrical power by gravitational force of falling or flowing water – Most widely used form of renewable energy – Once hydroelectric complex is constructed, • produces no direct waste, • Virtually no output of greenhouse gas carbon dioxide (CO 2) – 2006 : • Worldwide capacity 777 GWe supplied 2998 TWh of hydroelectricity in 2006 • approximately 20% of world's electricity, and 88% of electricity from renewable sources

Large Hydro ETC 288 Alt Energy

US Hydro Plant Distribution

World Hydroelectric Capacity ETC 288 Alt Energy Note*: Keep in mind what the production is for when looking at the %. Hydro is ~6% of Primary energy production which includes gasoline for transportation and heating oil etc. World renewable energy share as at 2008, with hydroelectricity more than 50% of all renewable energy sources.

List of Hydro by Countries ETC 288 Alt Energy Brazil, Canada, Norway, Paraguay, Switzerland, & Venezuela are only countries in world where majority of internal electric energy production is from hydroelectric power. Paraguay produces 100% of its electricity from dams, exports 90% of its production to Brazil & Argentina. Norway produces 98– 99% of its electricity from hydro sources.

ETC 288 http: //videos. howstuffworks. com/discovery/35623 -extreme-engineering-icelandic-hydropower-project-video. htm Alt Energy

How Hydro Works Videos http: //www. youtube. com/watch? v=c. EL 7 yc 8 R 42 k http: //www. youtube. com/watch? v=NWw. Ma_kjc. Bk&feature=related Student Produced: http: //www. youtube. com/watch? v=wvx. UZF 4 lv. Gw&feature=related http: //www. youtube. com/watch? v=bs. XSKNKM_6 g&feature=related

Hydroelectricity Advantages - ETC 288 Alt Energy Economic • Elimination of cost of fuel – Immune to increases in cost of fossil fuels - oil, natural gas, coal • Tend to have longer economic lives than fuel-fired generation, – Plants now in service built 50 to 100 years ago • Operating labor cost usually low– Plants automated, few personnel on site during normal operation • Where dam serves multiple purposes, hydroelectric plant may be added with relatively low construction cost, provides useful revenue stream to offset costs of dam operation – Tourist attractions, water sports, aquaculture, irrigation, flood control – Expected sale of electricity from Three Gorges Dam, Yangtze River, China, will cover construction costs after 5 to 8 years of full generation

Hydroelectricity Advantages ETC 288 Alt Energy Environmental • No CO 2 Emissions - No fossil fuels, do not directly produce carbon dioxide – Some carbon dioxide produced during manufacture & construction, but tiny fraction of operating emissions of equivalent fossil-fuel electricity generation • Research done by Extern. E project by the Paul Scherrer Institut and University of Stuttgart shows : – Hydroelectricity produces least amount of greenhouse gases & externality of any energy source • Coming in second place was wind • third was nuclear energy • fourth was solar photovoltaic. – The extremely positive greenhouse gas impact of hydroelectricity is found especially in temperate climates

Hydroelectricity Disadvantages ETC 288 Alt Energy • Ecosystem Damage & Loss of Land – Large reservoirs submerse extensive areas • destroy diverse lowland valley forests, marshland, grasslands • cause habitat fragmentation – Disrupt aquatic ecosystems - upstream & downstream • Ex. - Atlantic & Pacific coasts have reduced salmon populations - prevent access to spawning upstream, even with fish ladders • Salmon - on migration to sea pass through turbines – some areas transport smolt downstream by barge • Some dams, ex. Marmot Dam, demolished due to impact on fish. • Turbine and power-plant designs that are easier on aquatic life are active area of research – Changes in downstream river environment. • Water exiting turbine contains less sediment, can scour river beds, damage riverbanks – Ex. Grand Canyon, daily cyclic flow caused by dam contributes to sand bar erosion • Dissolved oxygen content may change • Water exiting typically much warmer than pre-dam water • Some projects - canals to divert river: Ex. - entire river diverted, leaving dry riverbed - Tekapo & Pukaki Rivers, New Zealand

Hydroelectricity Disadvantages, cont. • • Methane Emissions --- very potent greenhouse gas from tropical reservoirs – In tropical regions reservoirs may produce substantial amount of methane • Plant material in flooded areas decaying in anaerobic environment • Greenhouse gas emissions from reservoir may be higher than those of conventional oil-fired plant. • Reservoirs of Canada and Northern Europe, greenhouse gas emissions typically only 2% to 8% of any kind of conventional fossil-fuel thermal generation. – A new class of underwater logging operation that targets drowned forests can mitigate effect of forest decay Flow Shortages - Low energy production • Changes in amount of river flow will correlate with amount of energy produced at a dam Relocation - disadvantage of hydroelectric dams is need to relocate people living where reservoirs are planned – 2008, estimated that 40 -80 million people worldwide had been physically displaced as a direct result of dam construction. – In many cases, no amount of compensation can replace ancestral and cultural attachments to places that have value to displaced population – Historically & culturally important sites can be flooded and lost. – Examples: • Delta Lake, Rome area 1911 • Aswan Dam in Egypt between 1960 and 1980 • Three Gorges Dam in China • Clyde Dam in New Zealand • Ilisu Dam in Turkey Failure Hazard - large conventional dammed-hydro facilities hold back large volumes of water – Failure - poor construction, terrorism, or other causes can be catastrophic to downriver settlements and infrastructure. – Some of largest man-made disasters in history • Banqiao Dam failure, China, 26, 000 deaths, plus 145, 000 from epidemics, millions homeless

Comparison with Other Power Generation Methods ETC 288 Alt Energy • Positive: • Hydroelectricity eliminates flue gas emissions - sulfur dioxide, nitric oxide, carbon monoxide, dust, mercury • Hydro avoids hazards of coal mining & indirect health effects of coal emissions • Compared to nuclear power, hydro generates no nuclear waste, has no dangers of uranium mining, nor nuclear leaks. Unlike uranium, hydro is renewable source. • Compared to wind farms, hydro more predictable load factor. If hydro project has storage reservoir, it can be dispatched to generate power as needed – Hydro plants easily regulated to follow variations in power demand

Comparison with Other Power Generation Methods, cont. ETC 288 Alt Energy • Negative: Unlike fossil-fuelled turbines, construction of hydro plant requires longer lead-time - hydrological studies & environmental impact assessment – Hydrological data up to 50 years or more required to determine best sites for large plant • Unlike fossil or nuclear energy, number of sites that can be economically developed for hydroelectric production is limited: – in many areas most cost effective sites have been developed – new hydro sites tend to be far from population centers - require extensive transmission lines • Hydroelectric generation depends on rainfall, may be significantly reduced in years of low rainfall or snowmelt: – long-term energy yield may be affected by climate change – utilities that primarily use hydroelectric power may spend additional $ to build extra capacity to ensure sufficient power available in low water years.

Physics of ETC 288 Alt Energy Hydro Power • Calculating the amount of available power A hydropower resource is measured according to amount of available power, or energy per unit time because of the water's motion. There energy available because of motion can be divided into two parts: 1. Kinetic energy available due to g of drop h over a dam (acceleration) 2. Kinetic energy available because of the horizontal stream flow (momentum) • The amount of energy, E, released when an object of mass m drops a height h in a gravitational field of strength g is given by • The power (energy/time) available to hydroelectric dams is the energy that can be liberated by lowering water in a controlled way. The power is related to the mass flow rate. • Substituting P for E⁄t and expressing m⁄t in terms of the volume of liquid moved per unit time (the rate of fluid flow, Φ) and the density of water ρ, we arrive at the usual form of this expression: where • Using flow rate r = ρAv, the this can be converted into the simple formula for approximating electric power production at a hydroelectric dam power plant: P = hrgk – where P is Power in kilowatts, h is height in meters, r is flow rate in cubic meters per second, g is acceleration due to gravity of 9. 8 m/s 2, and k is a coefficient of efficiency ranging from 0 to 1. Efficiency is often higher with larger and more modern turbines. Not that this accounts for both the energy du to the drop (form hg) and the energy due to the momentum (from r) • If energy is due only to momentum: from d = 1/2 at 2 substituting h = 1/2 gt 2 and g = v/t then we use: Pwatts= ρΦgh = ρΦv/t(1/2 v/t)t 2 = 1/2ρΦv 2 = 1/2ρAv 3 ρ = 1000 kg/m 3 Use P =1/2 CeρAv 3 Ce = Efficiency of system

Derivation of Units Note: Watts = J/s = (N ∙ m)/s = (Kg m/s 2)/s = Kg m/s 3 1. Pkw = hrgk is an Empirical formula meaning it is a practical formula and works from observation h = m, r = m 3/s, g = m/s 2, K = ? hrg = m(m 3/s)(m/s 2) = m 5/s 3 (Not KW!!) What to do? Make k = KW s 3/m 5 Pkw = hrgk = m 5/s 3 (KW s 3/m 5) = KW 2. Pw = 1/2 CeρAv 3 is a theoretically derived equation that MUST be in watts Ce is unit less, ρ = kg/m 3, A = m 2, v = m/s kg/m 3( m 2)(m/s)3 = kg/m 3( m 2)(m 3/s 3) = kg m 5/ m 3 s 3 = kg m 2/s 3 = W So to get KW must divide by 1000

Method of Generating Hydroelectricity • ETC 288 Alt Energy Conventional Hydro – Most hydro power comes from potential energy of dammed water driving a water turbine & generator • Power extracted from water depends on volume & difference in height between source and water's outflow • This height difference is called the head • Potential energy amount in water is proportional to the head • Shown in next slide – To deliver water to turbine while maintaining pressure arising from the head, a large pipe called a penstock may be used

Conventional Dam Cross Section ETC 288 Alt Energy

Generator and Turbine ETC 288 Alt Energy

Pumped-storage Hydroelectricity ETC 288 Alt Energy • Type of hydroelectric power generation used by some for load balancing: – Stores excess energy in form of water - pumped from lower elevation reservoir to higher elevation reservoir – Natural geological features & adequate water supply needed • In some cases lower reservoir is the ocean -- sea water is used – Low-cost off-peak electric power used to run pumps – During high electrical demand, stored water released through turbines • Losses of pumping process make plant a net consumer of energy • System increases revenue by selling more electricity during periods of peak demand - prices are highest • Pumped storage is largest grid energy storage form available • Improves daily capacity factor of generation system

Pumped Storage ETC 288 Alt Energy Power Generation Diagram of the TVA pumped storage facility at Raccoon Mountain Pumped-Storage Plant.

Pumped Storage Power distribution, over a day, of pumped storage facility ETC 288 Alt Energy

ETC 288 Issues & New Alt Energy Developments in Hydro • Run-of-the-River Hydroelectricity – Natural flow & elevation drop of river used to generate electricity Smaller reservoir capacity • Divert some -- or most -- river’s flow through pipe and/or tunnel • Returns water back to river downstream • A dam – smaller than traditional hydro – required for enough water to enter penstock pipes --- lead to lower-elevation turbines – Run-of-river projects dramatically different in design & appearance from conventional hydro – Traditional hydro dams have enormous reservoirs-- flood large tracts of land – Most run-of-river projects do not require large impoundment of water --- key reason projects environmentally-friendly - “green power”

Run-of-the-River ETC 288 Alt Energy 31, 894. 8 Chief Joseph Dam near Bridgeport, Washington, USA, is a major run-of-river station without a sizeable reservoir.

Advantages Run-of-River ETC 288 Alt Energy • Can create sustainable green energy that minimizes impacts to surrounding environment & nearby communities • Advantages: – Cleaner Power, Less Greenhouse Gases: • as with all hydro-electric power, run-of-river hydro harnesses natural energy of water & gravity • eliminates need to burn coal or natural gas to generate electricity needed • Substantial flooding of upper part of river not required for smaller-scale run-of-river projects • Fewer people living at or near river need to relocate • Natural habitats & productive farmlands not destroyed

Disadvantages Run-of-River ETC 288 Alt Energy • Can't co-ordinate electricity output to match consumer demand • "Unfirm" power: considered an “unfirm” source of power – Little or no capacity for energy storage – Much more power during seasonally high river flows (i. e, spring freshet), much less during drier summer months • Environmental Impacts: – Small, well-sited run-of-river projects can be developed with minimal environmental impacts – Many modern run-of-river projects are larger, much more significant environmental concerns

Free Flow Low-Hydrological Head Hydro ETC 288 Alt Energy • Hydro that uses no dams or reservoirs http: //www. youtube. com/watch? v=w. Dg. Gv. Pd. Au. TU&feature=related • A low hydrological head type of hydro power (See http: //verdantpower. com/what-systemsint/) – A low-head hydro project -usually has fall of water less than 5 meters (16 ft) – Sites with less than three meters (about 10 feet) of head are generally referred to as “ultra-low head. ” • Since no dam is required, low-head hydro may dramatically reduce the following: – Safety risks of flash flood caused by breached dam – Environmental and ecological complications • Need for fish ladders • Silt accumulation in basin – Regulatory issues – Initial cost of dam engineering and construction – Maintenance • Removing silt accumulation. • However, low-head units much smaller capacity- require many more for energy production • Some costs of small turbine units offset by lower construction costs

Scales of Hydro • • ETC 288 Alt Energy Large hydro: More than 10 MW. Small hydro 10 megawatts (MW) is generally accepted as the upper limit – This may be stretched to 25 MW and 30 MW in Canada and the United States. – Small-scale hydroelectricity production grew by 28% during 2008 from 2005, raising the total world small-hydro capacity to 85 GW. – Over 70% of this was in China (65 GW), followed by Japan (3. 5 GW), the United States (3 GW), and India (2 GW). [ • Micro hydro typically produce up to 100 KW of power. – Can provide power to an isolated home or small community – Micro hydro systems complement photovoltaic solar energy systems because in many areas, water flow, and thus available hydro power, is highest in the winter when solar energy is at a minimum. • Pico hydro under 5 KW. It is useful in small, remote communities that require only a small amount of electricity. – For example, to power one or two fluorescent light bulbs and a TV or radio for a few homes. – Even smaller turbines of 200 -300 W may power a single home in a developing country with a drop of only 1 m (3 ft). Pico-hydro setups typically are run-of-the-river, meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before being exhausted back to the stream.

Micro Hydro ETC 288 Alt Energy Diagrams: http: //www. youtube. com/watch? v=S 4 B 2 g. ODY 3 Mk&featur e=related Working system http: //www. youtube. com/ watch? v=Ecyc. DAJc 858 Home system: http: //www. youtube. co m/watch? v=w 8 Iq 0 b 2 jw yw A Micro Hydro plant.

Support Required to Integrate Hydro Power into Grid ETC 288 Alt Energy • Hydro - fairly predictable & reliable source of electrical power • Prediction of power being generated at given power plant • Ranges from ht very predictable today, to much less predictable micro • In general, more the hydro is dependent on natural stream flow, more unreliable the hydro source • Required - transmission lines to bring hydro power from hydro plant location to high population areas

Description of the Hydro Forecasting System ~ 20% of the total world's electricity, 63% the electricity from renewables ~10% of US and about 85 % of renewabl US is now 4 th in the world, China #1

Water Cycle ETC 288 Alt Energy

General Forecasting Method Physics-based Models - use initial observed point conditions and laws of physics to create mathematical model Statistical Model Refinement - analyze history, calculate likelihood (correlations or probabilities) of weather event occurring based upon current conditions. Often used to adjust "biases" in physics models – i. e. terrain caused cool/warm bias

Specific Hydro Forecasting Factors • Must couple a hydrological stream flow model with meteorological model • Adjust forecasts using ground based and radar derived precipitation estimates • Antecedent soil conditions very important • Must adjust forecast based upon solid type amount of infiltration

Current Real Time Operational Location Lewis River Basin 1. Merwin reservoir 2. Swift reservoir 3. Yale reservoir © 2007 AWS Truewind, LLC

Observational Input Data Sources • Observational – Statistical • Precipitation • Streamflow – Distributed Model • • Streamflow Precipitation Snow Water Equivalent Temperature Relative Humidity Wind Speed Temperature Lapse Rate Terrain Height © 2010 MESO, Inc.

Model Input Data Sources • NWP Model – Statistical • Reforecast Database – Distributed Model • • Precipitation Temperature Relative Humidity Wind Speed Shortwave Radiation Longwave Radiation Temperature Lapse Rate © 2010 MESO, Inc.

Statistical Method © 2010 MESO, Inc.

Distributed Model (DHSVM) University of Washington Distributed Hydrology Soil Vegetation Model

Precipitation vs. Runoff Snow

24 -hr Ahead Streamflow Forecasts for Water Year 2007– Merwin Dam WA Comparison of 24 hour forecasts with 7 day average streamflow day of water year Oct Jan Apr © 2009 AWS Truewind, LLC Jul Oct

• End Lecture

Labs Exercise 1. Power Calculation Problems 2. Water Manager Exercise

Power Calculation Problems Using either the relationship Pkw = hrgk or Pw = 1/2 CeρAv 3 perform the following: Where ρ water = 1000 kg/m 3 Assessment 1. You have been hired to evaluate the power in KW that would be produced for a hydro power plant dam that would have the following characteristics: The distance of the head of the pipeline intake to the tailwater (base), is 4. 5 m. The flow rate in pipeline would be 850 m 3/s. g = acceleration of gravity = 9. 81 m/s 2 The efficiency of the plant would be 85 %. Assessment 2. You have also been hired to calculate the power in KW that would be produced from a Free Flow - Low Head Hydro system with the following characteristics Radius of the effective stream flow is 0. 2 The speed of the steam is 4 m/s The efficiency of the system is estimated at 80 %.

Water Manager Exercise Terms and Definitions • ESP = Ensemble Streamflow Prediction • Acer-Foot (AF) – Volume of water that will cover area of one acre to a depth of one foot = 43, 560 cubic ft. • KAF = Kilo AF or 1000 AF – Volume of water that will cover an area of 1000 acres to a depth of one foot = 43, 560, 000 cubic feet.

80 74 KAC-ft Volume 60 45 40 20 20

80 74 Max KAC-ft Volume 60 75 % - below (25 % above) 45 50 % - above below 40 25 % - below (75 % above) 20 20 Min

80 74 KAC-ft Volume 60 45 40 20 20

80 76 KAC-ft 70 Volume 60 45 40 20 20

80 76 KAC-ft 70 Volume 60 45 40 20 20

80 76 KAC-ft 70 60 Volume 54 45 40 30 20 20

Scenario • You are the water manager for a reservoir that supplies a large metropolitan area – Dam 500 feet high • Capacity of the Reservoir 500 KAF – 500 KAF corresponds to 250 feet • 1 foot ≈ 2 KAF – Over 500 KAF will cause topping of the dam and flood the town – Safe max release (channel capacity downstream) = 2 KAD/day (use 60 KAF/Month) – Minimum environmental Release = 0. KAF/day (use 15 KAF/month) • Goal - have highest water height (elevation) on August 1 without ever flooding town downstream • Starting water height is 225 feet (450 KAF)

Forecast from ESP Per Month

March 1 Make a Release Schedule Max is 60 KAF/month & Min is 15 KAF/mo Start 450 KAF (250 ft) Fcst In Total KAF March ____ KAF + _____ = _____ April _____ KAF + _____ = _____ May _____ KAF + _____ = _____ June _____ KAF + _____ = _____ July _____ KAF + _____ = _____

March Forecast from ESP Per Month

Make a Release Schedule Max is 60 KAF/month & Min is 15 KAF/mo Start 450 KAF (225 ft) Fcst In Total KAF March __-20____ KAF + __10__ = _440__ April ___-25____ KAF + __15___ = _450_ May ___-30____ KAF + _ 40____ = _460___ June ___-25 ____ KAF + __45___ = _ 480___ July ___-35_____ KAF + _55___ = _500___

April Forecast from ESP Per Month Actual in March 15 KAF

April Make a New Release Schedule Max is 60 KAF/month & Min is 15 KAF/mo Actual Increase was 15 KAF Start 445 KAF (222. 5 ft) Fcst In Total KAF April ___-20 ____ KAF + __15___ = _440_ May ___-30____ KAF + _ 40____ = _450___ June ___-25 ____ KAF + __45___ = _ 480___ July ___-35_____ KAF + __55___ = _500___

Extra Slides