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xfconf-query, crontab, "Failed to init libxfconf: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11."

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#!/bin/bash
status=$(xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac)
vid="/dev/video0"
if [ -z "$status" ]; then
    exit 1
if [ -e "$vid" -a "$status" -gt 14 ]; then
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac -s 14
elif [ ! -e "$vid" -a "$status" -eq 14 ]; then 
    xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac -s 25
It works perfectly when run it from the terminal. However, from crontab I get this error. 
Failed to init libxfconf: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11.
Here is my crontab entry. It was edited using crontab -e.
*/5 * * * * (bash -x /home/brock/bin/vid-power) > /home/brock/Desktop/debug.log 2>&1
Here is the full output of my debug.log.
~/Desktop$ cat debug.log 
++ xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac
Failed to init libxfconf: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11.
+ status=
+ vid=/dev/video0
+ '[' -z '' ']'
+ exit 1
I have tried various solutions, including the comment here and this one, but none have worked. 
I did the following, it allows me to invoke xfconf-query from crontab:
First, get the value of this variable:
echo $DBUS_SESSION_BUS_ADDRESS
You will see a path like this:
unix:path=/run/user/1000/bus
Then use, in the script executed by crontab:
export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$UID/bus
xfconf-query ...
Credit: https://bbs.archlinux.org/viewtopic.php?pid=1706208#p1706208
I will just set this script to run as a Session and Startup > Application Autostart item instead.
#!/bin/bash   
vid="/dev/video0"
while true; do
    status=$(xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac)
    if [ -e "$vid" -a "$status" -gt 14 ]; then
        xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac -s 14
    elif [ ! -e "$vid" -a "$status" -eq 14 ]; then 
        xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/inactivity-on-ac -s 25
    sleep 5m
In order for the xfconf-query command to work under cron environment you need to have the following in the bash script, for example:
# set today's wallpaper; first set one env variable for xfconf-query
export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$UID/bus
xfconf-query -c xfce4-desktop -p /backdrop/screen0/monitorVGA-0/workspace0/last-image -s "${filename}"
Credit: https://bbs.archlinux.org/viewtopic.php?pid=1706208#p1706208