Shining a Light on U.S. Household Solar Energy Generation

An ongoing visual exploration of residential solar panel adoption.

• How does the US generate its solar energy?
• Do sunny states generate more solar energy?
• Which states have the most solar panels?
• How have states' tax incentives correlated with solar panel adoption?
• How have other factors impacting adoption changed?

View the R Notebook here.

Dependencies

A list of R packages used in this project, sorted by purpose:

• Data Analysis
  • tidyverse for everything
  • magrittr for extended pipe functionality
  • lubridate for dealing with date objects
  • here for OS-agnostic filepaths
  • readxl for reading Excel files
• Visualization
  • ggrepel for neater text labels
  • gghighlight for simpler highlighting
  • geofacet for arranging facets in the shape of the US
  • ggridges for plotting distributions over time
  • extrafont for... extra fonts
  • gridExtra for combining plots
• Geospatial tools and data
  • sf for geospatial data structures and operations
  • zipcode for geocoding by zipcode
  • noncensus for geocoding by state and county FIPS
  • rnaturalearth for US state-level shapefiles
  • rnaturalearthdata for high-res versions of above

Data

Data Sources

Note: Datasets are omitted from repo due to large file sizes, but are all publicly available and fairly straightforward to reassemble from the links. Assembly steps are laid out in the section below.

Dataset	Source	Description	Unit of Observation	Last downloaded	URL
State Energy Data Systems (SEDS)	U.S. Energy Information Administration	Data on solar photovoltaic energy generated by all U.S. sources (utility, commercial, industrial and residential sectors). Data available for 1960 - 2016.	State-year	Jan 28, 2019	Link to site
OpenPV Project	National Renewable Energy Laboratory (NREL)	Database of public data for photovoltaic system (i.e. solar panel) installations in the US. Core dataset from the Lawrence Berkeley National Laboratories (LBL). Data available for 1969 - 2018.	Solar panel installation	Jan 19, 2019	Link to site
Solar Summaries	National Renewable Energy Laboratory (NREL)	Average solar irradiation data by state and zipcode. Data available for 1998 - 2009	Zipcode-month	Jan 19, 2019	Link to site
Database of State Incentives for Renewables & Efficiency (DSIRE)	NC Clean Energy Technology Center, North Carolina State University	Database of incentives and policies that support renewables and energy efficiency in the US. Data available for 1975 - 2018.	Incentive or policy	Feb 6, 2019	Link to site
U.S. Population Data	National Cancer Institute	Aggregate dataset of Census data and annual decennial estimates of population by state, race, age, and other characteristics. Data available for 1969 - 2016.	State-year	Jan 19, 2019	Link to site
Cartographic Boundary Shapefiles - Counties	U.S. Census Bureau	County-level shapefiles at 500km resolution for all census tracts in the U.S. as of 2017.	County	Feb 6, 2019	Link to site

Data Assembly

1. Raw data is downloaded from the public sources above and organized in the /data directory by category like so:

data
├── data-population-estimates
│   └── us.1969_2016.19ages.adjusted.txt
├── data-power-generation
│   ├── Codes_and_Descriptions.xlsx
│   └── Complete_SEDS.csv
├── data-solar-irradiance
│   └── solarsummaries.xlsx
├── data-solar-panels
│   └── openpv_all.csv
├── data-state-policies
│   └── dsire-2019-01
└── shapefiles-usa
    ├── cb_2017_us_county_500k
    └── cb_2017_us_zcta510_500k

2. data-import.R file in /scripts directory takes the raw data in /data and outputs an .RData file named solar_data_master.RData.

3. solar_with_commentary.Rmd loads the .RData file accordingly. The primary output is the solar_with_commentary.nb.html file that is rendered here, and .png images of each chart is saved to /output.