Author Archives: Brad Horn

The Renewable Energy “Duck Curve”

The California grid operator (CAISO) has a high of share of  renewable energy.  CAISO has adopted a mascot that sums up the challenge: the duck curve.

The chart at left presents the duck curve.  It shows net power load during the day.  CAISO defines net power as the difference between forecast load and expected power production.  In certain times, net load curves have a “belly” in the middle of the afternoon given a surge in solar power production.  The chart then shows a rapid ramp-up in net load – as much as 13 to 15 GWh – as solar production declines and demand accelerates in the early evening.

Posted in Solar, WECC | Comments Off on The Renewable Energy “Duck Curve”

Solar Energy in Qatar: The Business Case

Qatar_Solar_LCOEThe economics for solar energy in Qatar are challenged by some of the lowest natural gas prices on Earth, combined with a local and subsidized electricity tariff with retail power prices of $0 to $27.40/MWh, commercial prices of $24.66 to  $41.10/MWh, and industrial power prices of $19.18/MWh.

Notwisthstanding, there is still a solid business case for solar energy in Qatar given the rapid decline in capital costs since 2009, and the ability to generate revenues from displaced domestic gas demand that results following the introduction of renewable energy capacity.

Posted in Economics, Natural Gas, Project Valuations, Qatar RE, Renewable Energy, Solar | Comments Off on Solar Energy in Qatar: The Business Case

Super Cheap Solar Power for Dubai

DEWAplotThe Dubai Electricity and & Water Authority (DEWA) just completed a tender for 100 MW of solar PV, and the delivered power system price is an amazingly low $0.059 / kWh.

Typically, the leveled cost of energy for solar PV is between $0.085 – $0.11 / kWh for GCC countries given solar irradiance, use of high efficiency panels, and cost competitive engineering. The low end of this range is best suited for vertically integrated OEMs with EPC services, or IPPs with scale in equipment purchasing who buy modules close to the cost of goods sold.  But IPPs with low construction costs are making their mark.

Posted in Economics, Project Valuations, Solar, UAE | Comments Off on Super Cheap Solar Power for Dubai

Popularity of R Programming Language

TIOBE IndexThe popularity of R is rapidly increasing and is well on its way to being a top 10 programming language.  The TIOBE index is a standard indicator of the popularity of all programming languages.  The TIOBE index confirms that a subset of languages – those for computational statistics and data analysis – are gaining increased attention. The clear winner of the pack is the open source programming language R.

Posted in Data Science, R Programming | Comments Off on Popularity of R Programming Language

Qatar Solar

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German Renewable Energy Output Tops Lignite

German Renewable Energy OutputGerman renewable energy output became the country’s most important power source for the first time this year, according to Agora Energiewende.

Energy policy in Germany has entered a new phase with nuclear power being permanently phased out. The old controversies are a thing of the past: there is a broad social and cross-party consensus concerning long-term political and energy goals. It is no longer a question of whether the energy system will be overhauled in favour of renewables, but how to go about doing this.

Posted in Germany, Renewable Energy | Comments Off on German Renewable Energy Output Tops Lignite

Wind and Solar Capacity to Pass Nuclear

Nuclear, Wind, and Solar Capacity

Sources: IAEA, EIA, Bloomberg New Energy Finance

Wind and solar capacity are expanding  rapidly and each is well on track to pass nuclear power capacity.  Advocates of nuclear energy have long been predicting its renaissance, but the installation of nuclear capacity appears to be stalled with little to no change in recent years.  Wind energy, by contrast, will have more capacity installed than nuclear by 2015 and solar energy capacity is likely to pass nuclear prior to 2020.   

Posted in Data, Nuclear, Renewable Energy, Solar, Wind | Comments Off on Wind and Solar Capacity to Pass Nuclear

Glare from Solar PV Modules

PV_array_glareA common question concerning the safety of photovoltaic (PV) power systems is the impact of reflected sunlight.  PV modules have the potential to impact neighboring structures or activities, notably aviation.  It is important to know where the reflected light will go and what the intensity of the light will be at any point in time.

Posted in Dust, Engineering, GIS, Irradiance, O&M, Projects, Qatar RE, Solar | Comments Off on Glare from Solar PV Modules

Inverters and Inverter Manufacturers


Inverter Cost Components; GTM Research

Inverters are key components in any photovoltaic (PV) power system.  Inverters convert direct current (DC) to alternating current (AC).  They control power factor (e.g. reactive power) and ensure power output quality aligns with downstream equipment specs.  And finally, they play an essential role in the protection, operation and communication philosophy of the solar power plant.

Posted in Engineering, Equipment Vendors, Solar | Comments Off on Inverters and Inverter Manufacturers

Renewable Energy and the Carbon Majors

CarbonMajorsThe business case for renewable energy and CO2 reduction is changing as carbon tracking and court cases shift focus from carbon emitters to the ultimate producers of coal, oil and natural gas … to the “carbon majors.”

A 2013 study published in the journal Climatic Change cites 90 companies by name and responsible for 63% of human induced greenhouse gas emissions since the beginning of the industrial revolution.  National industrial plans (NIPs) and energy companies from the US and Europe dominate the list with familiar names like ChevronTexaco, ExxonMobil, Saudi Aramco, British Coal, and RWE.

Posted in Qatar RE, RE Policy, Renewable Energy | Comments Off on Renewable Energy and the Carbon Majors

Aerosol Animation

Aerosol Optical Depth (AOD) defines the degree to which aerosols prevent the transmission of sunlight by absorption or scattering.  AOD is measured using an integrated extinction coefficient over a vertical column of air.  The extinction coefficient can be used to analyze solar extinction and the performance of solar power systems as a function of location and time.


Posted in Animation, Data, Dust, Meteorology, Modeling, Qatar RE, R Data Import, R Graphics, Resource Assessment, Saudi Arabia, Solar, Spatial Analysis | Comments Off on Aerosol Animation

Crop Raster Images in R

E020N40The maptools package has a pruneMap() function t0 crop map objects in R.  In practice, the function extracts data from SpatialPolygon or SpatialLine objects given a boundary box or specific area of interest.  Unfortunately, there is no equivalent function for high resolution, large data, raster images, which are common in many Earth Science applications.  The following post defines a custom function to crop raster images in R and to extract data from SpatialGridDataFrames.  The function is tested using a raster image from the Shuttle Radar Topography Mission (SRTM; shown at left).  The resulting data is then mapped using the image() function in R.

Posted in GDAL, GIS, R Data Import, R Graphics, Spatial Analysis | Comments Off on Crop Raster Images in R

R Source Code

WordcloudSource code access is one of the great benefits of R.  Source code is available for base R and over 5,000 open source packages.  There are many reasons to view source code: to know what software does when documentation is vague or incomplete; to combine code objects in custom scripts or libraries; and to change source code as needed.  The following post defines the different types of R source code available and how to access R sources.

Posted in R Packages, R Programming | Comments Off on R Source Code

Qatar National Grid (QND95)

surveyingQND95 is a two dimensional coordinate reference system that is the standard for geographic mapping in Qatar.  QND95 is intended for onshore activities only. QND95 provides up-to-date specs to calibrate surveying tools, GPS devices, GIS tools, and analysis activity.  The coordinate reference system facilitates standardization and consistency across activities. 

Posted in GDAL, GIS, Qatar RE | Comments Off on Qatar National Grid (QND95)

New Solar Technology – LCOE Roadmap Qatar

NREL_Best_Research-Cell_EfficienciesBloomberg has released May 2014 PV Spot Prices with current module costs (COGS), margins and sales prices.  This data is extended to profile the levelized cost of  energy (LCOE) for solar PV technology, and is combined with new solar efficiency data to define the LCOE roadmap for solar energy in Qatar going forward.

Posted in Economics, Project Valuations, Qatar RE, RE Policy, Solar | Comments Off on New Solar Technology – LCOE Roadmap Qatar